Usually the one with actual tits wins the titfight. The same should go here. Alyssa with an incredibly easy win.
It's not a titfight, but I think your prediction is correct.
Heather, you niece is absolutely gorgeous, but unfortunately I don't think she's going to look the same once Alyssa get's through with her. Judging from the pictures, I can't see anything but a one sided domination of poor Wendy.
I imagine you'll probably try to jump in and help or break it up if things go south for Wendy, but I have a feeling from that picture that Alyssa's aunt isn't going to let you. I can't say who I'd take in you against the aunt, but I think that Alyssa will be through with Wendy long before you and Alyssa's aunt are finished. This will give Alyssa plenty of time to humiliate poor Wendy in front of her fiance. Hopefully for Wendy that won't rekindle feelings her fiance has for Alyssa. Otherwise, this could end up a mess. If Alyssa does get done with Wendy first be on the lookout because she may try to double team you with her aunt.
Hopefully, things work out OK, but in this case OK might be managing to get your niece out of there before Alyssa puts her in the ICU or a plastic surgeons office... Don't mean to sound negative, just how I see things shaping up. I wish you both goodluck.
Can you post the outcome when this goes down?