How to Construct an Unambiguous Joint Possessive that Follows a Verb?

How to Construct an Unambiguous Joint Possessive that Follows a Verb?

I've read that when writing about multiple possessors who jointly posses a thing, the common practice is to add a Saxon-genitive ('s) to the last noun in the series. (E.g., John and Mary's cats refers to cats owned by both John and Mary.) Whereas, when writing about multiple possessors who individually possess separate things, the common practice is to add a Saxon-genitive to all the nouns in the series. (E.g., John's and Mary's cats refers to two sets of cats: John owns one of the sets, and Mary owns the other set.)

However, joint possessives can be ambiguous when they are placed immediately after a verb.
For instance, I sang to John and Mary's daughter, could mean 'I sang to a guy named John and I sang to this girl who said she was the daughter of a woman named Mary', or 'I sang to a female who calls her father John, and calls her mother Mary'.

Is there a solution to this problem that's recommended by grammarians or linguists?

Thank you

Please don't answer with a recommendation that the construction be avoided. Whether in life or in language, I don't believe that it's helpful to tell a person that they will not be faced with a problem if they stop trying to solve it. Solving a problem (especially a novel one) does more than solve the problem at hand: Solving a problem helps the problem-solver become better at solving problems.

Answer

I sang to John and Mary's daughter.

This is ordinarily understood to express your 'I sang to a female who calls her father John, and calls her mother Mary'. John and Mary is a single conjunctive expression standing in a genitive relationship to daughter.

If you want to distinguish this from 'I sang to a guy named John and I sang to this girl who said she was the daughter of a woman named Mary' you must explicitly divorce John from conjunction with Mary. This is most efficiently accomplished thus:

I sang to John and to Mary's daughter.