You won't be able to have her in a carrier whilst the seatbelt sign is on - they have a special seat-belt attachment which attaches to yours and has to go around a baby's/child's waist. But you can have her in a carrier at any other time if you like.

Feed on take-off / descent (or offer a dummy if you use one, if she doesn't want a feed). Some babies aren't bothered by the pressure (my DS never was), others are. Feeding is the best thing for it.

Babies are SOOOO easy to fly with at that age. Seriously! I flew from Cairns to either Sydney or Melbourne (by myself) with DS when he was 3 and 4 months, and with DP as well at 6 months, then again just a few weeks ago (15 months), and once they are mobile but before they can be easily entertained whilst sitting still is the most challenging time to fly with babies, because they don't understand why they have to sit still. We took a few hand puppets and sang songs and read books to DS and he was fantastic this last trip. Usually it goes much better than you would expect. And with a one hour flight, it will be over before you even know it.

Tips:
- Change her just before you board, and unless she poos, you won't have to change her whilst on the plane. For longer flights, people who use cloth nappies will put their bub in a night nappy so that they don't have to change as frequently. (Can't remember whether you use cloth or sposies).
- Put her in clothes that are easy to change, with minimal buttons and fiddling.
- Pack a spare teeshirt for yourself.
- Keep the bag with hers and your stuff in it under DH's seat (if you are holding her), so that he can get to it easily if she is asleep on your lap.

Good luck!