She was awarded her PhD in 2009 from the University of Texas at Austin, where her advisor was David Buss, and went on to do a postdoc at UNC Chapel Hill.

[2][6] Since her postdoctoral fellowship at UNC Chapel Hill,[2][6] Fleischman has been a lecturer in the department of psychology at the University of Portsmouth from 2011 to 2020.

[16] Fleischman wrote an essay in 2023 titled You're Probably a Eugenicist arguing that Dor Yeshorim goal of reducing the rate of Tay-Sachs disease and cystic fibrosis in Jewish families could be described as Eugenicist and that "Gay men and lesbian women in the US often use gamete donors from egg and sperm banks to have kids in a process that is transparently eugenic ... Organisations that recruit egg and sperm donors don’t just recruit for fertility, they also screen for mental and physical health, height, education and criminal history – because that’s what their clients want and expect.

"[2][17] Fleischman has been described as pronatalist, notably saying "I encourage people who are responsible and smart and conscientious to have children, because they’re going to make the future better.

[20] Fleischman is a member of Giving What We Can, a community of people who have pledged to donate 10% of their income to the world's most effective charitable organisations.