I'm in the same boat. I just had my 2nd child 3 weeks ago and will graduate in June. I too deferred the match and was contemplating doing research in my year off to "fill my resume" with something. However, as I'm home with my newborn, I realize that I don't want to take time away this year to just add fluff to a resume. My priority is and will always be my family and medicine is second. Years from now I'll never regret spending time with my kids but I may regret doing something that takes me away from them. My opinion is this: your kids are young but once. You'll never get this time back. If you start sacrificing family time now, it will be that much easier to do so when you are a super-busy resident/physician.
I'm all for being a great mom for a year. I hope you join me!