Unfortunately as it is a work function, I would see if several folks would pitch in on one gift (I am sure there are some that feel as you) and don't go/give a wedding gift. That keeps the peace and makes it more affordable although this situation is clearly not acceptable and this young lady needs to learn some manners. Thank goodness you have some. If others can't or don't want to than I think the other options suggested such as the charity or what you can afford are clearly acceptable solutions. You are the bigger person here.