
I wouldn't be too concerned just yet. Is she otherwise fine? As long as there is no nasty smell, I would give her a chance.
Having said that, I'm surprised how many times I haven't even seen them, the bitch has snaffled it that blooming quickly!
I have always tried to remove some myself, before they get chance to eat the lot. This time, Suzie was so fast that she gulped down the placentas for the first 3, and a few minutes later the lot came back up, and I had chance to remove them. After another 3 pups she did exactly the same. I had dozed and missed number 7 (thought she had finished) so I guess she ate that one.
I try to let a bitch have some, as it's a normal instinct, but if it's a large litter like this one, if they eat the lot, they have the smelliest loosest poo and it's stinky.