well my daughter is 36 lbs with clothes on...so hopefully she will fit just fine. She is tall torso'd, and just tall all together lol.
We will be checking my sons carseat......BUT I bought a suitcase for it. (my daughter actually rides in a radian xt in our car, and my son in a britax blvd, both RF'ing.) I am going to bring my daughters radian xt for my son, since it folds. We bought a very sturdy suitcase for the radian, and we pad it well....we did this on our last trip to Florida. I know you all don't recomend checking car seats....but I feel pretty confident that it is well protected....but also know that if something does happen, I will be running to the store to buy a light weight, but sturdy seat for him!
We are not purchasing a seat for him on the airplane...I know I know, it's the safest, but right now we only have a year left until we HAVE to....so we chose not to.
So anyways, hopefully the vest fits my daughter. I think my mom is going to order it here pretty soon. I'm actually happy about having the vest, because it's not as cumbersome as a car seat. Now in my van and my mom's car she has a car seat and still rear faces because she can, and having her in the car seat all the time is just easier.....But, sometimes when we are up at my parents house in Alaska, she wants to ride with Papa, and he doesn't have a car seat in his truck for her (a truck with a back seat)...and we just don't want to uninstall, reinstall, then uninstall and reinstall again for a quick trip to the store....so teh vest will be handy for that too.