Going to try something here. I'll assume you are correct, and no matter how skilled she gets at fighting, she will have a disadvantage against someone stronger without experience. I don't think that's the case, but i'll go with it.
So let's take three instances.
Instance A: She has no experience whatsoever, in fighting or martial arts, weighs 130 and is attacked by a guy weighing around 200. She probably has about a 1% chance (maybe less) of winning, considering she doesn't know how to react and the guy was prepared. so 99% chance she gets mugged/beat up/raped/killed/kidnapped/whatever.
Instance B: She has no experience whatsoever, in fighting or martial arts, but does do aerobics and/or a martial art at a place that does no practical application. She weighs 130 and is attacked by a guy weighing around 200. She probably has about the same 1% (or less) chance of winning, considering she still doesn't know how to react and the guy was prepared. so 99% chance she gets mugged/beat up/raped/killed/kidnapped/whatever.
Instance C: same lady now has about 10 years of experience in BJJ (likely crosstrained some striking at some point from my experience with BJJers, but that's irrelevant). She still weighs 130, and is attacked by the same guy weighing around 200. She still has a disadvantage, but knows something that she can do to protect herself. Now she has a 5% chance of reacting and using her skills to sub the guy and escape, 95% chance of all trhat other stuff. I feel like I'm lowballing her chances, but that's also irrelevant. Even if it went to a 2% chance it would be irrelevant.
In the third instance, the person has a better chance of winning/surviving/whatever, even if it is still extremely low. So that increased chance is the benefit.