I have a 9 week old jack russell terrier. This morning I woke up really her to her vomiting, it was two quarter size piles, white and creamy. Then, for the next three hours her stomach was making loud gurgling sounds, VERY loud, and when I put my hand on her stomach I could feel her intestines churning and such. She didn't seem in pain, just frustrated cause she would try to sleep and the noises kept waking her up, she eventually got to sleep and they stopped but returned when she woke up. She refused her breakfast or water. She's usually very energetic in the morning, but has only been sleeping today. She pooped earlier this morning, and it was softer than normal, but I wouldn't say diaherrea, she peed recently, but hasn't gone to the bathroom other than that. Also, a yellowish, very snot like mucus was leaking from her butt when she was sleeping.

This is her first week with us, she's had all her first shots and had her first deworming already. The first couple days home she had a very healthy appetite, but it tapered off. She would still eat about half her serving at each mealtime so I figured she just wasn't all that hungry. She's being fed Nutri source.

Yesterday she got into some adult dog food so I'm hoping her stomach is just upset from that. Does that sound right, or should I be worried? How long should I let it go before taking her to the vet?

Is there any way she could have gotten into something? A plant, cleaner, anything poisonous?

She got to go to on a trip to my mom's house yesterday, I was there the whole time watching her, the only things she got into were the adult dog's food(he has crohn's disease and is one specialized food, but I don't know the name) and she chewed on a cat toy for a couple minutes that had cat nip in it but I took that away.

Could the cat nip toy do this?

Cat nip does make dogs throw up. I think you should call the vet and describe what is going on. Play it safe.

Not as worried anymore, she ate a few bites and had a drink

What are you feeding her? Is it the same thing the breeder was feeding?

She could just have an upset stomach from her food being changed.
Sometimes puppies will just have an "off day" and will throw up maybe once or twice.

If diarreah lasts for more than 48 hours or the puppy is vomiting excessively you need to go to a vet immediately.