I’ve done this and had both champagne and sparkling cider on hand. All parents gave permission but if even one had been hesitant, it would have been sparkling cider for all under 21s. I don’t want anyone to feel left out or that their mom is lame just because she’s uncomfortable.
As an aside, the cider was more popular (I have a great source in Quebec and they will ship: http://en.cidreriebilodeau.com)