I have never used respite care, although I really could use it
. Personally, I don't think you should consider it for only two weeks (I don't even think you could), and just to "make" a child's Christmas. First of all, I may be wrong, but I believe the purpose of respite is to help the caregivers recoup some of their energy and get a break, not necessarily for the benefit of the kids.
Parening these kids is VERY draining and exhausting. I don't think it is to give kids a taste of the good life. Hopefully, they are being well cared for in their foster home (although sadly, some are not) and would already have a nice Christmas with their foster parents. If you are thinking kids would come to you for respite care directly from their birth families, I don't think it works that way. You would get kids (quite likely hard to handle kids) from their foster parents so their foster parents can get some rest and time for themselves. If anything, it would probably be a bit traumatic for the child (even though the foster parents need the break) to move to yet another home, even temporarily. Holidays can be really tough for these kids anyway. So don't imagine that they would be thrilled and greatful to have an "awsome Christmas".
I don't mean this in any way to be harsh. Poople new to all this aren't expected to know everything, and that is why we are all here...to learn and to share knowledge. As I said, I could be wrong, as I have not used or provided respite care. I will be curious to see other people's responses. Good luck.