IMHO, even though you are mature, you are still young yet and so is this young woman.
The good part about this is that you have learned that even though you were hurt, you can find another girl that is exciting to be with and that you "can" connect with another female.

Yes, you feel love for this girl too, but you really should allow yourself to step back and just see where this leads. This girl is young too, and she has discovered she really likes being with someone other than her boyfriend. This time she has away from you isn't about cheating either, she is going to be looking at this boyfriend in a different light and she may realize that she has found someone she likes even more in you. It sounds like this has caught her off guard and she isn't sure what to do about it. I think that's pretty normal given her age.

Even though you may be mature for your age, you are going to mature even more and as you continue to mature, you "will" meet others along the way that "could be" good partners too. That is what this experience is teaching you the most right now. And, to be honest with you, that is also what this young girl is also learning too.

You had a breakup that you reacted badly to in your past, you just discovered you can heal and love someone else and do better things and enjoy yourself, that was good for you, the main lesson you learned is "to keep going forward" and new people can come into your life that are fun to be with, and can bring a spark of love too, and that old relationship was not all that, which you can see better now. Well, just see where this leads with the knowledge that it can actually happen again for you too. Twenty two is so young yet, you will mature so much more than you realize, and along the way you will meet others that will fit with that new level of maturity, that is really the reality of this time in your life too.

If this girl decides to choose to stay with this boyfriend, let that go, it just means you didn't really find the right match, that is all, just know that you have learned that you actually "can" grow and change and mature and meet another person that is exciting and wakes you up with feelings of "love".