I wasn't born too close to any holidays, but my little brother and I are only a couple days (and 6 years) apart. When I was a kid, after he was born, I always had to share my birthday party.
And our daughter was born on our anniversary, so we don't really get to celebrate that anymore, but that's ok. She was a great anniversary present.
I don't have any suggestions, but I wanted to say how sorry I am for the loss of your Dad, congratulations on your son's birth (on Christmas Day!), and a sincere thanks to your husband for his service.