Traveling with toddler & baby

Hi,

Tomorrow myself, my 2yr old daughter, my 6mth old son & my cousin will be traveling to go visit family. I have never traveled so far with the kids without my husband and although I will have my cousin there to help me, I am still a bit worried about the trip. My daughter generally doesn't travel well when we go by car just 3hrs away let alone 1.5hrs in a plane, then 1hr in a bus, then 3hrs in a train and then 2.5hrs in a car.

Not only am I worried about the kids coping & behaving I am also worried about having enough hands with all our luggage... I am going to have a suitcase, a carry on bag (not sure if I can fit everything in my backpack so might have to take the shoulder nappy bag), plus my strider pram. I'm also taking my baby bjorn so when the pram is folded I have my hands 'free' to carry other things. My cousin will have her suitcase and her laptop bag too.

So I am writing all this to get people's advice, recommendations, experiences on traveling with multiple young kids. How did you do it? Did you find it to be ok - especially traveling with a pram? (which as you know, the strider is quite big and as we have the two seats, has to be dismantled into two pieces to fold). We are flying with Jetstar.

Thanks in advance for any handy tips you can throw my way =)