It will not happen
1. she'd have to have been on title for approx. 12 mo.
2. the lender won't allow a NON occupant Co-Borrower
3. loan amount too low for most banks to even consider
4. you're only as good as your weakest link, your husband's credit. A perfect co-borrower is irrelevant
You need to look for a Private Investor, maybe a family member and offer to give them a good return on their money (8% to 10%) and mortgage on your home so they can be sure they will actually get paid back.