People are (rightfully so) really picky on mascara so while the thought is really really sweet I probably wouldn’t. I wish there was some way you could see what’s in her Ulta or Sephora cart if she has one lol (although of course I would never look through my partners phone.) All makeup is in fact pretty specific to the individuals taste, skin type etc so unless you want to come out and ask if she has been eyeing anything in particular I’d stick with clothes :)