My black labrador has a very swollen stomach, it doesn't seem to bother her, should I be worried.?

I have an 11 week old black labrador that we brought home yesterday, when we got home it was time to feed her, she was soooo incredibly thin when we got her and when we filled her dish she emptied it just as quickly as we put it in. Her stomach immediately doubled in size, it doesn't seem to bother her at all though, I can tell that she has a little build up of gas in her stomach but she doesn't seem to have any symptoms of bloat besides of a swollen stomach (a family member has a dog that suffered bloat) and she has just recently been dewormed for the second time, is this just from going to from having to share food with 11 other dogs (plus she was the runt in the litter) and being able to eat or is this something we should be worried about before her next visit to the vet in 2 weeks.