I think 3 too, the school day is going to be long enough for a newbie without adding an extra 90 mins of travel in, and as you are not 100% sure where you will end up, it might work out that she may stay anyway? I'm not a big fan of wasting time in the car, but I'm a city slicker!! LOL
FWIW I went to 3 different primary schools (we moved a bit), I wasn't overly outgoing as a youngster, but made friends easily enough. Knowing your DD, I think she will make friends pretty easy too, so in the worst case scenario that she changes schools, she is likeable, nice and kind - she'll cope well. And teachers are usually very supportive in helping a new kids transition to a new environment.