No way would I go to Boracay at Christmas, we were there at the end of April and it was way too crowded (as in you couldn't walk along the beach or the beach path without shoving your way through). Christmas time would not be relaxing at all and would be very busy, also the rates for accommodation are hiked to completely stupid prices at Christmas. Remember that the Philippines is a Catholic country and the number of people travelling there over the Christmas period to see family is huge.
We live in the Philippines and every year we leave at Christmas as it just gets silly. The last 2 years we have been to Thailand, other years we have spent it in India and Indonesia. I would definitely choose Thailand with a kid though, the travelling there is much easier.
