So I guess the question here is ... what is a Jack & Jill? I assumed from the original post it was a "bridal shower" that includes fundraising, raffles, baskets, etc.
If you are saying that Jack & Jill only means a co-ed shower, then I would say they are very common these days. My DD has one put on by their MOH & a groomsman BUT they only invited friends aka young people.
I think it is the whole raffle, fundraising part that many have never heard of, or are uncomfortable with.