I've never had engaged in homosexual behavior nor am I a woman, so I can't testify to much but other homosexual women and men do seem to claim it was their choice and I can't imagine how one could falsify their claims.
Bindle has made her position clear in a number of places:
https://www.newstatesman.com/politics/2014/07/julie-bindel-theres-no-gay-gene-and-i-love-idea-i-chose-be-lesbian