Hi becky23,
I think Test Track may be a little intense for a DD4. Mine is 5 and we didn't take her. While it's a relatively mild ride as far as "thrill rides" go, there are loud noises, sudden stops, and the outside ride may be frightening. I'd see how she does on, say, Splash Mountain before attempting Test Track. Just my $0.02.
Sincerely,
Len