K.Z.
Babies do wake up at night to practice new skills. Standing is the new thing and she wants to do it all the time! Sounds like she's getting ready for walking! My son did this too.
I don't think letting a baby cry is necessarily the best option. It may work for some, but it doesn't work for all, just know your child. My husband let our son cry it out once while I was working in the basement with the door closed. Apparently he cried for 2 hours!! And DH just ignored him (checked on him but wouldn't pick him up)!!! He was hysterical by the time I got to him. Another time I was away and he cried for 1.5 hrs. He is very persistant and higher needs, and he would cry until someone picked him up and held him. So I held him a lot and when he'd wake in the middle of the night to try a new skill (sometimes babbling in his sleep as well), I'd talk softly to him, rub his back, and tell him it was time to sleep, he could crawl or walk in the morning when the sun is up. I don't see any reason to change his personality. It is trying at times, but I know he will grow up to be a leader.
Also, don't forget, as soon as you get used to the way things are (as in sleep schedules, eating habits, abilities), they change! No kidding! Keeps mom on her toes! Try to go with it and not get frustrated or think anything is wrong. It's all necessary to their learning process and there's no need to "break" it.