I’m having a hard time envisioning exactly what you mean by pushing her body into yours. If that happened to me (and it has on buses and at concerts, and there was “wood” invovled if you know what I mean) then I would slam my purse or elbow into them and shout very loudly, “What the hell are you doing!? Back up or I’ll call security.”
Please explain a little more clearly exactly what this lady is doing.
Some people, men and women tend to get too close to other people, especially in lines, because they don’t understand boundaries, like what @wundayatta said. Those kinds of people creep me out. Other people may accidentally get pushed into me, and I can deal with that, and politely move out of the way, or say “pardon me” and it’s fine.
There are plenty of women, I usually see this in clubs, that rub up against guys that they’re interested in. They usually accompany that move with a very silly laugh, even if the guy hasn’t said anything funny, and they tend to twirl their hair (even if they’re in their 40’s). They also might pretend to show you something on your arm or your face or your chest, so that they have to touch you. These people are usually drunk, but not always.