Repost from 08...Invitation address question

Ok I sent out my e-party invites which were a nightmare to deal with...Problem is that i still have about 15 to send out, i am waiting for FH to give me the addresses ...I just spoke to his mom and she gave me like 2 but then with two others this is what she told me to do and i really dont know how i should do this

Ok I had already sent out one invite Fh's aunt, but now she is telling me to send another invite to his aunts house but its for her daughter and daughters husband, the daughter remarried recently and she doesn't have the address or even know her new last name...She said she will get the last name but to send it and put in the address 'in care of aunts name' since its getting mailed to her house...Is there a proper way to do it...i hope i explained this right and its not too confusing.

Same situation with someone else, i am supposed to send their invite to someone elses house but they don't have the husbands name...

Another invite i have to send it to their cousin and his fiance but they dont know her last name.

I really don't know what to do, i am basically given this info and supposed to send out but i cant be rude, i cant put and guest when someone is engaged.

Don't know if there is an answer for this...I seriously can't take this invitation BS anymore lol, ive had one problem after another