Born in La Grange, Illinois on December 31, 1895 to an Alabama-born father and college graduate mother, Hazel started painting as early as age 5 using her mother's leftover paints. Throughout childhood she studied painting, and by the command of her father, secretarial studies, since to him artistic wages were not predictable ones. While in high school, Mrs. Hannell also studied at the Saturday morning classes of the Art Institute of Chicago. She graduated from the Emma Church School of Art in Chicago. For income Hazel and her friends worked for Marshall Fields designing chintzes. During that time she learned to love Oriental Art and tuned into the "effect of Divine Intelligence through nature on her heart and mind". In 1987 Hazel revealed her inspiration to the Chesterton Tribune: "Hamada, a Japanese master potter, says you really ought not have to sign things, your works should be recognizably yours." As Hamada, many of Hazel's works lack signature. Works from earlier years such as her watercolor Self Portrait (1934) bear a signature in the same medium. It is worth noting that upon many of her works a penciled signature has been placed after their departure from her possession.
Hannel's spirit as an activist took root during her college years. In a letter from her nephew Wilbert Reuter to former director of the Brauer Museum of Art, Richard H.W. Brauer, "There was great concern…when she brought disgrace and dishonor upon the entire family, and its name, by appearing in a public demonstration supporting women's suffrage." Mrs. Hannell's moral compass would lead the way toward great regional changes as well. While renting a studio from the Church School of Art on Michigan Avenue in Chicago in the 1920s, Hazel met Vaino Hannell, a Finnish-American artist she would marry on December 31, 1923. Oftentimes for money the two were commissioned for a variation of small projects. While living in Chicago in the 20s, the first pottery of the Hannells' was a group of fountain tiles done for a Chicagoan architect Arthur Hoyne. Hazel recalls that the two "had a reputation for either being able to do things or knowing someone who could" and that they "did all kinds of things; from murals to papering wastebaskets." They even worked with Jane Adams at the Hull House for some time. Hazel was inspired to join the Prairie Club, an organization that aimed to ease the ills of industrialization, by a friend because she "admired her and her taste so much." So, on the weekends the Hannells visited the Indiana Dunes National Lakeshore with a group of weekend painters including Fred Biesel, Frances Strain, and Harriet Rex Smith, and Jens Jensen, among others. Its beauty also drew artists like Frank Dudley, whose paintings would eventually aid the Dunes preservation projects. Together they walked along the beach and documented its beauty. Her subject matter consists mainly of the flora and fauna in its natural habitat in the Dunes. The Hannells and Biesels were closely acquainted, and together they led a movement against the conservative jury system in connection with Chicago art exhibits in the 20s. Vaino was part of The Ten, a radical group that had been instructed by George Bellows at the Art Institute in their production of controversial realism. In 1928 along with known artists Frances Strain, Fred Biesel, Hannell and Vin went on a trip to Paris and Finland. While there, they visited with the Dalstroms and the parents of Janet Sullivan, founder of the Art Barn and school of rural Valparaiso. This trip inspired her to repeatedly paint lily-of-the-valley, native to Vin's home in Finland but also to the National Lakeshore. After their return to the States, as well as many weekend trips to the Indiana Dunes to visit Biesel and Strain, Vin and Hazel were drawn to Furnessville, Indiana.
World War I came and their financial situation made it necessary for the Hannells move to their getaway home near the Dunes in 1930. Hannell tried to get a secretarial job, but that soon ended. "I got fired for being impertinent," Hazel said in an interview with The Seattle Times, "One of the foremen told me to do something and I was annoyed with him and I said, 'I won't'," even though I'd already done it." Within Hazel was a fire that would not go out. In Indiana, Hazel and Vin used that fire to run a pottery business. They created a potting studio from a chicken coop, lived off Vin's government pension, and used the regional clay to gain an income from which a living could be sustained. Regionally as well as in Chicago's Merchandise Mart, Hazel's work was featured throughout the 30s. This is where Hazel gained her fame. A wholesaler saw some of their work and offered her a business deal. Former director of Chesterton Art Center Gloria Rector reported, "Hannell once said that her clay pottery was their bread and butter during hard times." "To make a living as a painter, you either have to be a salesman or have a salesman," Hannell explained to the Vidette Messenger in 1983, "Pottery sells itself." The 1940s brought that salesman: a New York agency offered to market it nationally, putting the Hannells' work into department stores and gift shops all over the United States while providing them with a substantial allowance, as well as publicity.
It is true that many of Hannell's works of pottery were for dinner-time, but the shape and design are identifiably of her hand and design. An article in Craft Ceramist Utopia from the 1950s tells of her "stunning centerpieces of piled up artichokes, onions, peppers, etc., all done in a solid finish of gold of pewter with matching treatment in the dinner wear, enough to transport the buyer to the world of Cellini." Oftentimes Hazel designed the pieces and Vin would fire them. Hannell's method of applying the designs to her pottery involved an oriental brush with cobalt (blue), copper oxide (green), iron oxide (brown), and pewter glaze. The beauty of her cobalt pieces is known well among collectors of her work. Clem and Nixon Hall of New York, a designer-distributor organization, brought "their years of design and merchandising experience to the end that Hannell pieces fit market demands." A feature of the couple in The Gary Post-Tribune spoke of the Hannells' open to the public studio in which, "Vin would probably be watching over the two electric kilns, where the articles are fired," or would be checking "the infra-red, electric lamps, which provide a quick-drying method for the newly made cups and saucers." Her pieces are not perfect in form and often include bulges or indentations allowing for easy handling. This was done purposefully as a counter to the industrialization against which she often protested. "Some people seem to like the factory-made look," she told the Chesterton Tribune, "I'm a little inclined not to bother with it; the pieces are more interesting if they're not all exactly the same." On the pottery dune grasses can be found, bending in the wind, flora such as the lily-of-the-valley, or privately done calligraphy. Hannell also designed a series of clay angels and women figures such as the Madonna from Indian red clay.
In 1952 Porter County area residents began to hear that the area was being bought up by major steel making facilities. Hazel and Vin became charter members of the Save the Dunes Foundation, and in 1958 the first bill to preserve the Dunes was introduced after bus trips from Save the Dunes Council to testify before Congress. Hazel went on one of these trips to Washington D.C. along with founder Dorothy Buel. A video on the foundation of Save the Dunes talks about the women bringing a Dudley painting to Congress to show to the lawmakers the beauty of their homes. The Hannells even donated some of their land to the Indiana National Lakeshore, claiming they, "wanted Congress to know that the people who didn't want it were not the majority here." Meanwhile, she was capturing the beauty of the Indiana National Lakeshore in watercolor paintings in hopes that they would aid her audience's value of the environment.