I think driving is worth it but, if it's five hours, I suggest driving one day, staying in a motel, and testing the next morning. Trying to do all of it in one day is going to be a lot for her. Sorry if this is obvious.
A word of caution, though, that you still might not understand what she needs even after testing. Mine tested DYS and scored highly on the SAT at 11 but I have no clue what to do with that information. The school thinks all is good and that all their teachers can give him enough.
I'm fairly certain he is not getting enough challenge but I have no idea what to do about it. He has already skipped one grade and is very young for his age (11) so another grade skip up in to high school is probably not a good idea. He doesn't want to homeschool.
I think testing can be very beneficial but be aware that it's not going to give you all the answers.
You wrote: "someone please tell me exactly what my child needs, in detail, year-by-year to meet her intellectual and emotional needs." Wouldn't that be LOVELY to have? I would love it if someone would just send me a roadmap on what to do with my kiddo.
I don't mean to be negative. It's a hard road and it's hard to know what to do with all the information once you have it.