Pretty sure you can take two items FOC. Also, when you check in, ask for an aisle seat. Last times I flew with jetstar, paid to choose my seat - didn't get what I had picked. On the way down, they stuck everyone with a baby by the window! I was stuck next to two big guys, who also used the iPads they have on board so hell of a mission to get out to change DD's nappy! On the way back, I made sure they gave me an aisle seat as that is what I had paid for grrrrr you might be able to find info on their website as to what you can take for bubs rather than calling.