DD will be 4.
We arrive in LA at 7pm (3am UK time) and by the time we get through immigration and get to our hotel it will be 10pm (6am UK time). DD will get around 6 hours sleep on the plane (4pm take off, probaby asleep by 8pm, wake up an hour before landing) and I expect will sleep a good few hours when we arrive, but I am still expecting her to be up and ready to start her day at 4am and ready to crash by lunchtime.
Any suggestions on how to overcome the jetlag? I guess we will make her take a nap for the first couple of days when I haven't planned anything, but after that we want to make the most of Disneyland etc.