Seems like you to talk some sense into your husband first. There’s no point in saying “this is stupid” while acting “I’ll support you unconditionally”.

Ideally you’d discourage her in this decission and not support her financially. If she really wants to do it, she can pay for it herself. There is not much you can do about that, except discourage it. But you can’t do that as parents unless you’re both on the same page.