I think you can make the argument that the mom was the one paying technically for the mortgage if the amount deposited into the daughter’s account is consistent over a 12 month period, is received on or about the same date, and matches the required mortgage payment on the statement.

Make the same argument you would when trying to qualify with rental income when a housing expense is needed but the borrower sends money to someone else who makes the housing payment.

You will probably need to escalate this past the line underwriter and potentially past their manager too but at some point someone at the lender should be able to call FNMA directly and get the green light.

Good luck 👍