So apparently there are female versions of genderless robots.... Mrs Nannies. I guess it makes sense, with how much people bitch about "muh female characters" it would make sense a big robotics conglomerate would act on the safe side and make a female Handy. Altho then there would probably be issues with their "Binary identitites" so I think just leaving the Handys as genderless would've been a smarter move. More completely unnecesary Retcons. They could've just used a female Synth if they wanted the robosexual romance so badly.... remember when FO New Vegas made fun of wanting to fuck a Fallout robot? Now this game just plays it straight.
Please assume the position.
Looking at the wiki, it seems like you can transfer the Handy into a female synth body so you don't feel so weird about yourself. Anyway, I'm expecting a Dogmeat romance mod any day now.