I know I dont know you at all haha but I just wanted to give my 2 cents. I think if you make it clear WHAT the money will be going to that nobody will complain. I would say it would be no different than asking for cash as a present, which should be perfectly reasonable if there is a valid reason to ask for cash such as the couple bought a home and need to do renovations...or...IVF!! I'm sure you will have no problem