I want to give $15k each to my daughter, her husband, and their two children for a total of $60k/yr. I see this example all over the internet, but no details on what this actually looks like. Since my two grandchildren are both minors, how do I give them the money in the most flexible way possible? My current thinking is that I should ask my daughter to open a joint checking account with all 4 of them on it, but would they be able to spend the money on anything? For example, could they use that $60k to pay off the mortgage, or would they need to only use $30k to pay off the mortgage since it is in my daughter and her husband's name? What about regular expenses like groceries, etc?
Edit: I am not trying to prevent my daughter from spending it any way she likes. I want her to have the most flexibility, but stay within annual exemption (otherwise I'd just give the $60k directly to her). I actually want them to spend it as a family on anything they want/need, not be worried about the legality of keeping $30k in the grandchildrens' names.