Lilo & Stitch: The Series - Season 2 Episode 6 -

Experiment 089: SKIPLilo's hurry to grow up is immediately satisfied when Skip, experiment 089, arrives and ages her up to a 17-year-old and then a 27-year-old. Lilo soon realizes she wants to be age 7 again because she misses out and ruins the future. She must figure out how to "reset" herself.