From a cursory glance, it seems to depend on the establishment. Legally, drinks with less than 0.5% alcohol could feasibly be sold to minors, but many places will enforce age verification checks anyway for the sake of being responsible. Part of this seems to be because the packaging rarely distinguishes itself from the alcoholic alternative very well, meaning there's a chance the latter could be sold to a minor unintentionally. (Source)Man, what a shame.
Not sure why she couldn't get a non-alcoholic one, aren't they like soft drinks?