If you are worried about ganja smoking you are going to the wrong Island. As far as Seastar I have been there a few times and haven't noticed any ganja smoking but like anywhere else it is a possibility. That being said, I think they would have a blast at Seastar. When we were there there were all ages including little ones having fun and dancing.
It is a great place for you and your family to have a good meal and lots of fun.