I have seen Teddy's baby teeth come out - it was interesting to watch him paw at his cheek, run around nervously, and then when it finally came out, he spit it on my kitchen floor and walked away. He had 6 retained baby teeth that had to be pulled two weeks ago when he was neutered.
You can tell the difference between adult teeth and baby teeth because the baby teeth are like little sharp pins and the adult teeth are not as pointy or piercing and are more contoured.
PS If your 9 month old does not let you open her mouth, you might want to work on this with her daily -- smear a small amount of peanut butter on your fingers and let her lick and then stick fingers in there and handle her mouth. You should be able to look in there - what if she got into something you had to retrieve? I did this with my puppy Teddy and he now accepts my fingers in there without issue. I've done these annoying things to my dogs throughout their lives and believe me it has come in handy.
Good luck
