Why does my dog lick her plush toy like it's a baby?

I have a nine-year-old JRT. She has tons of toys and chooses a new "favorite" every once in a while. She can get kind of protective with them and growls if my other JRT just walks by them, even though the other one has no interest; she only likes tuggies and balls. They are both females.

Anyways, got a little off track. With some of her favorite plush toys, usually bigger ones, she will lay on the couch with them and lick them to death like she is cleaning them. It looks like affection almost. Why does she do this? Can dogs really get that attached to a toy? It's not beneath her to destroy one though when I'm gone out of separation anxiety...I think she knows I'll stitch the favs back up. She snoops in my sewing room for them...lol. Sometimes she'll dash out of there with one when she thinks I'm not looking before I can repair it.