Question about a woman's behavior at a party...

My gf and I went to a party yesterday (and if you’ve followed my Q’s you know she and I are in a weird place right now, but anyway…) and early on I noticed one of the women there who seemed younger—maybe mid-late 20s would just kind of get lost in staring at one or the other of us. At first it seemed like she was in a mood or something because she seemed bothered by something (almost like a mad dog stare), but it kind of fluctuated between that and a gaze. My gf left early, and after she did, this woman spent a significant amount of time totally making eyes at me—but less sexy eyes and more of a gaze or an intense stare—not unfriendly by any means, just not super googely or girly or eyelash batting or any of that. I’m kind of a gazing type myself, so in a way it was nice to encounter a rare someone who doesn’t find that uncomfortable. When I got home later, my gf remarked that she noticed this woman sort of following this other guy around the party—a particularly handsome, quiet guy, although my gf’s take was that he wasn’t really biting. I didn’t really notice that dynamic until she mentioned it. My gf didn’t seem to notice that this woman was staring at us from time to time.

Anyway… I can be kind of a blockhead in these matters, so I’m curious to know what may have been going on there—in terms of what a woman would be thinking and whether she’s a creeper or something like a guy would get branded a creeper or something more benign or what.

Addendum: we also had normal conversation amid all this, so she wasn’t totally high or something as far as I could tell.