But that didnt stop her going for male Shep in ME2 on a suicide mission and being human.
Exactly my point. She never continues after that with female Shepard. As far as I can see, and I've said it before in almost every one of these threads that pop up out of no where, pre-existing characters should be left alone. I'm not sure about Kaidan or Ashley since there really isn't enough character development/background to those characters, but I honestly can't see it happening either. But for recurring characters, like both Tali and Garrus, they both had two years to stew on their feelings for Shepard, then the entirety of ME2. I don't see why either of those characters couldn't have done a romance with Shepard during ME2. But the S/S option wasn't and option. For whatever reason, they didn't include it.
Her having the same lines up until the branching point could simply be chalked up to resources or time. Having to write one set of lines, with one or two alterations, is easier and less time consuming than rewriting the entire script for any given character.
Though, I'm also not entirely sure what you're trying to say with your reply.
My main point is "Why do these threads keep popping up, there's a dedicated one already."
But, also, see above if you feel like it.