FYI my DD is now 11 and now loves ToT. But when she was younger (as young as 5-6) there were several times when we would make it all the way onto the ride and she would change her mind.
The very first time she rode it (in WDW) She was probably turned 5. I had told her everything (I thought) about the ride. I neglected to tell her that her bottom would come off the seat!

She refused to ride it for a few more years after that. Now she says it's her favorite DCA ride.
She went through a similar thing with Haunted Mansion. Rode it with my DNiece and was fine. Next time we rode it she backed out at the last minute (just as we were boarding Doom buggy). We exited through the last minute exit. Took her awhile to agree to ride it. Still not one of her favs. though she's already excited about doing it at WDW with all the new stuff.