Nope, she wants to get married, she can pay for it herself.
No parent is under any obligation to ever pay for a wedding. If they want to great, if not.. then the adult bride and groom need to figure out a way to pay for it.
My husband and I married very young. We told our parents. My husbands parents said, "we do not give you permission'. We told them, "we were not asking permission, we were informing them'. They then said, "we will not help you with the wedding', we told them, 'we were not asking or expecting any money, since, if we could not afford our own wedding, we certainly, could not afford to be married or we were planning to expensive of a wedding"..
It took us a year to save the money for the Wedding, the reception and the week long cruise honeymoon. i even paid for the brides maids outfits and we paid the rentals on the Tuxedos.. Our friends were also young, so we knew they also could not afford these items..
If this grown daughter really wants to get married, she will figure out a way to finance it..
IF your husband wants to give them money, but does not have much, he should be honest. I would love to pay for your wedding, But I only have $500. to give you.. Everyone is an adult, no need to dance around the subject..