Your sister should be able to do the free trial, but you have to have the peak membership to bring a guest. It costs about the same as both of you having a membership.
Actually The member ship allows you to have a guess my suggestion would be to get the one membership and then always have your sister as your free guess the other thing is is that the memberships at crunch you have to be 12 and up so your. I'm so your sister does fit the age criteria
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