[luckylady]

Wow, what a predicament! What problem does your mother-in-law have with having a 4lb Yorkie come to visit if he is as well supervised as you say? Has she had problems with him being there before that you know of or could tell (if maybe she wasn't saying anything). How many people will be there; maybe she's afraid he'll get hurt (stepped on, etc, I'm grasping for ideas here)with alot of people around. Hopefully you have a good enough relationship with her to maybe talk if over with her and see what, if any, the problem really is, and see if you can get her to change her mind. If not, well, unfortunately it's her home, so I suppose you'd have to abide by it. I can see how that would put a damper on the day, not only missing your baby but maybe some hard feelings towards the in-law. Isn't there a close friend of yours that you could entrust the care of Teddy with while you're away?
Hey, I see other posts...yea, the hotel idea is a good option also.