As I have mentioned in past years, the key to kids partaking in kitchen projects, and having them be enjoyable to all, is all about prep. That and some rimmed cookie sheets, if it involves cookie decorating.
If they're little, get things organized and then invite them to help. If they're old enough to help, encourage them to get things set up for younger siblings... having everything at arm's reach makes it easy to share.
Making a pastry bag out of a sandwich-sized zip-loc, with a tiny hole cut in the corner works well. Older children can make precise lines...and younger ones, well, it helps to keep the frosting contained.
I don't know about your children, but the attention span of mine is not long enough to make dough, roll, cut, bake, cool and then decorate. So, I made a big batch of gingerbread again this year and froze the cookies until this weekend, when we had time to do the fun part: decorate.
That said, what is most important is that you keep things merry. If you don't have time to bake before Christmas, no. big. deal. I love Meagan Francis' perspective on holiday baking. Forget the calendar, heck, go out and buy cookies and a tub of frosting if that's what works. You and I both know that what matters is that you actually enjoy time together this holiday season, decorating cookies... tromping out in the snow... snuggling up with a book...or whatever family time bring these next two weeks. I hope you all have a wonderful vacation together and will look forward to kicking off the New Year with some health-inspired, simple recipes to share with your families!