Congrats to your Daughter and her fiance. I was a December bride too
1. Tell your daughter that her future husband can NOT get away with "this is your Christmas/Anniversary" gift unless it is one hell of a gift.
Mr. 1228 jokingly wanted to set our wedding date for December 27 so he could do the one gift for Christmas, anniversary and my birthday. I didn't fall for that! 
2. Set a budget and plan a timeline for doing things
3. Ebay is your friend
4. you can be elegant but comfy on your wedding day.
5. relax and breathe
When the stress gets to you, sit down and go to this wedding site
Etiquette Hell
and go to the wedding section and be prepared to :
1. laugh your ass off
2. tell your family and friends "if I act like this please kill me!"
This is
HER wedding, don't forget that. Let her lead and plan
Good luck!