You appreciate it! That's what you do. Appreciate that maybe your girlfriend can avoid getting assaulted, along with her friend(s) she may be with. Watch Fear the Night!
My buddy is a doctor who only works here and there to maintain her license because she has 5 boys, two of whom have special needs, and the hubs can support them easily, she has a black belt, and takes two of her boys to classes. I think you should consider big picture; do you need someone you don't love, but can't fend for herself? I think you should ignore your jealous friends when they give you grief about it.
My best advice would be to grow up, and value the total package. Don't listen to your dummy friends picking on you.