The four-year-old can for sure go. The two-year-old might be a bit young and it might be a bit scary for her because it goes pretty fast. I noticed that a lot of the young kids got scared by that. I would probably call the facility regarding your two-year-old niece. That just seems like if she were to fall off she could get seriously hurt.
Must be 38" tall or a parent must sign a waiver.
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