Oh man... poor baby! We had the same problem when my son used to go to daycare, from the time he was about 13 months to 17 months. He actually got bit several times over the course of that time, and every time the daycare had to fill out an accident report and had us sign it. Everything like that SHOULD be documented.

Now here's my question- what was your 6 month old daughter doing in the same room as a kid old enough to bite like that? Usually children are segregated into different rooms by age, 2 year olds with 2 year olds, infants with infants, etc... And obviously your daughter is not old enough to actually provoke a biting, so where was the supervision there? Odds are, the kid who bit her has a history of doing it, and if that's the case, he should be removed from the daycare; at the very least, watched VERY carefully and supervised at all times.

You did the right thing by taking pictures... I suggest keeping those and getting some sort of documentation from the daycare as to what happened. They at least owe you an explanation... and maybe even the money you paid for Chloe to spend the day there that day. I hope it all works out for you and she's bite-mark free soon!