How on earth were they sexualized?
Well, it's not a blatant form of sexualisation like some instances, but when Ripley starts off on the Sulaco
, she's dressed in a full jumpsuit with leather coat, by the time she fights the Queen (and I'll allow some leeway for it being a hot and humid environment), she's ditched the top half of the jumpsuit, leather coat, given a massive gun and wearing a sweat-soaked T-shirt. It's pretty tame by today's standards, but it could be argued she's intended to be far more sexy/badass by the end of the film than near the start - and then there's the scene with her and the others emerging from the cryosleep tubes.
With Sarah, it was mostly in Terminator 2
- giving her tank tops for most of her wardrobe. Again, this can also be equally attributed to the "make her look badass" aspect as well.
Similar arguments could be made for The Bride, Rey and Furiosa.
None of them were there to be romantic interests to male stars.
Except Ripley sorta was to Hicks by the end of Aliens
, and Sarah Connor was to Kyle Reese (hey, a Micheal Biehn double!)