Hi mommas! I'm not quite sure if its posted here or not yet. Tried to search but couldn't find it.

It's going to be our little one's first international travel next month, 19hrs with 1hr layover (she'll be 4.5 months by then). Any advice regarding choosing airline seat? Lap or get her own seat? Gate check or checked-in carseat? I know they let passengers with infants board first but should we wait until everyone has boarded and see if we could get a better seat? Perhaps anyone of you can give me any tips/tricks. Thanks in advance!😊

Here's a photo of our dear Allie for attention😍