baby dyke
n.— «But the times, they are a changing. I am what is called a baby dyke (a lesbian under 24) and part of a new generation, who still care about women’s rights, but rally just as ferociously for MAC lipstick, Angelina Jolie and a shallow night out with the girls.» —“Bring on the dancing girls” by Hila Bouzaglou Mail & Guardian (South Africa) Jan. 12, 2007. (source: Double-Tongued Dictionary)
FYI
This phrase has been around subculturally for at least 15 years.
Research in LBGTQI media and literature will back that up.
Thanks for your fascinating language page!