It took us until Max was 18 months old before we flew from CA to RI. Since he was so early and has chronic lung disease, planes were a big no-no for us, because there are just too many germs on planes. I would say that your situation is not that extreme. However, remember that Christmas time is also Flu time. And that more people get sick on planes now than they did 20 years ago because they recirculate the air instead of piping in fresh air. So, you may want to delay your visit until the flu season is over in late april or early May. However, if you do decide to go, here are a few tips.
Have your husband preboard with the carseat (you can get your daughter a half price seat if you call the airline direct, not online) She can fly for free on your lap, but I would recommend a cozy seat for safety and germ control. So when your Dh boards, have him wipe everything down in your row with Clorox wipes, the belt buckles, the arm rests, the walls, the air outlets, tray tables, everything. Remember, the airplane just had people on it before you, so this will limit spread of germs.
You and baby board at final call. They wait until the very last minute to check strollers at the gate, so you can carry her right on. this limits her sitting in a car seat and getting antsy while everyone else is boarding.
Feed her a bottle at takeoff and decent to help ear pressure stabalize.
Most likely she will sleep, but don't take her in the middle of her night time sleep, especially if she is sleeping through the night. Part of our flight cut into Max's regular night time sleep schedule and when he got woken up from the decent, he was just that much more angry and hard to console.
Take a new toy, if she is old enough to be interested in toys. Along with a couple of old toys. She will play with all of her old toys first, getting bored of them quickly, and then when you pull out the brand new toy, she might stick with it longer.
My pedi said, Absolutley don't change his diaper on the plane. The bathrooms are too germy. She said it won't kill him to sit in a pee diaper, and if he does number 2, try and keep him in it as long as he can. And if I absolutley have to change a poopy diaper, do it at the seat. HOWEVER, the airline doesn't like when you do this. They will yell at you. So DH should be on the lookout and make sure your baby wears something comfy that is easy to get a very quick change done. Luckily Max never pooped, and I just changed his diaper in his stroller before we got on the plane and when we got off.
I hope this info helps.
DH, John (36)
Max, 1/20/03, 25 wks, 1lb. 3ozs. (IUGR), severe PE
#2 is on the way, EDD at 36.5 weeks is 3/24/04