With an MFA in Painting from The Art Institute of Chicago, Howlett was one of the first designers hired into Microsoft in 1985.
Working in Microsoft's typography group, she collaborated with Matthew Carter to develop a number of typefaces including Verdana (which is named after her daughter, Ana).
In it, she explains the design process and provides a number of makeovers of real-world software products.
It is recognized as one of the first books to bridge the gap between artistic product designers and technical software engineers.
She maintains a studio in San Diego and exhibits work throughout the United States.