Thin chinchilla

We are in the process of moving, so I've been neglecting my chins a bit.
They've had all the food, water and hay they need, but I have not had the time to talk as much with them as I normally have.

I had noticed that one of our females - Minipiv - was a bit on the thin side, but I wanted to give it some time, and see if she could gain some weight on her own.
My mom has been looking after the animals when I've been to the new flat, but she doesn't really notice the small things. It's not something I blame her for, you really need to know the animals in order to notice the small problems.

Anyhow, when I got home last Friday, Mini was a lot thinner than I had expected, so I had to call the vet Monday. In the mean time I got some critical care into her, just to be on the safe site.
When I got to the vet, she could feel there wasn't really any food in Mini, and a weight at about 480 grams - way too low.
When looking at Minis teeth, the vet couldn't really see anything because of some food in her mouth, so we agreed I should come back today, so she could get a closer look at her.
The rest of the day we - Nicholas and I - spent a lot of time with Mini, warming her and feeding her some mush made of some Critical Care, boiled water and her pellets.
She must have been hungry for quite a while, because she ate like a crazy. I have been watching her though, and have seen her eating, but I guess she has had some problems grinding down the food and swallowing it.
She began pooping a lot, and got a lot more energetic, even though she never really seamed that low on energy.

Today the vet still had a problem seeing anything, so they kept her, and I have to call them back in a while.
I'm hoping everything went smooth, and there's nothing seriously wrong. I think it's a minor problem with her teeth, and hope it will be over today.
I am a bit worried though. It's never a good feeling leaving your animals at the vet.