Using tithe money to help with wedding

Dear Rabbi, My sister is getting married to a young man whom my parents disapprove of. They told her that they’re not going to help her with her wedding expenses, although they will attend the wedding. They both work, but, as far as I understand, right now they don’t have any money. I told my sister that I would pay her for a professional makeup artist with my tithe money. Some time has gone by, and now our parents decided that they will help her with wedding expenses after all. I know that if I do not pay for her makeup, they’ll pick up the tab. Can I still sponsor her professional makeup with my tithe money? An unrelated question: we are planning to hold a sheva brachos banquet for the young couple. Can I finance this with my tithe money?  

Dear …!

If the young couple is in a situation where they’re allowed to accept tithes, you are allowed to help them with your tithe money, even if someone else could help them instead of you.

You cannot use your tithe money for anything that is a family obligation. Therefore, if in your family it’s an accepted practice that family members organize sheva brachos, then you are not allowed to finance it with your tithe money.