Yes, it was my experience as a 16 year old as well, at probably 50 kg. Good thing they were fat, slow and not serious. It was tough, at times painful, but it went fine. I had tougher physical challenges several times per week from two of my teammates in particular, getting clobbered a few times is nothing compared to what a physically developed and highly determined junior will put you through every single duel. The worst senior players football has to offer, which is what the competition will be, don't have the will or ability to keep that up. They're shit, and they play for fun and the beers after.
This woman is used to playing against tougher players physically than I was. She thinks she can do it, and her teammates think she can do it. You don't.
I know for a fact that women can get through pickup games with grown men, because women participate in those all the time, and that can get just as brutal as amateur matches.
If a woman can't measure up physically against the men, but still is good enough to get in the team, that means she is simply a better footballer than them to make up for it. When I played, I was extremely physically weak, fell over at the slightest duel and basically never won a duel unless it was a sliding tackle, I caught someone off balance or I cheated. I was tiny, and a few of the girls I knew that were physically stronger and faster than me. However, I never missed if I got the ball inside the box, so I could still compete. Not at a high level, but we're talking low level amateurs.