Hi Teri!
Thank you for bringing your question to the Disney Parks Moms Panel!
Please don't be nervous! Walt Disney World is a place for fantasy, magic and escaping the worry of everyday life.
You should be completely fine. While I normally have the correct number on our reservation, there have been times on trips with large groups that our numbers have changed. Sometimes we have less, but I can remember three times we had more than the number our reservation was for. Twice was at
'Ohana and once was actually at
Be Our Guest Restaurant. They were able to accommodate us each time. (Note - we only had two extra Guests, I don't think they would be able to accommodate a large number of extra people, but two infants should be no problem.)
You may have a bit longer wait as they free up space, but they should be able to seat you fairly close to your reserved time.
I hope this helps! Please let me know if you have any other questions and have a magical vacation!
~Lori