A lot of the songs on Street Hassle are about her. I don't know a lot about her but she was probably cool, being Lou Reed's girlfriend and all.
Lou also wrote a song about Candy Darling, "Candy Says," and referenced her and another transgender woman, Holly Woodlawn, in "Walk on the Wild Side," but I don't believe he had a romantic connection with either of them. They just were part of his social circle in the 1960s.