Cookie is (like many other Goldens that we know) very sensitive. If I'm stressed, she's stressed. On days like that, her poop is very thin and (since I always pick it up in a plastic back to throw away and keep the streets clean - I automatically check it) slimy and greenish. Otherwise no problems.
She also has this, when my parents have been here with their dog and she's on her own again.

She never ever vomits after she's eaten something. And even though she loves to chew, she will never go as far as destroying them. All she gets for snack, are those dried sardines (maybe 2 or 3 a day) and on chewy stick after we finish our dinner and she hasn't been begging. For training we use those little sausages for kids.

The vomitting happens usually in the middle of the night, lets say after about 7 hours of sleep (she goes to sleep at 7pm till the next morning 7 am) or after the early morning pee.

I'm very concerned about it and I don't feel satisfied about the vet telling me she's alright.

My husband thinks it has to do with her dreams (she's a very heavy dreamer with shaky legs, growling and barking).