>>He has been my sole source of income for the last 5 years, paying every single expense I have
That would be a gift, not income.
If he paid the expenses directly, it's a gift. If he gave her the money to pay, it's still a gift.
As gifts, they are not taxable until it reaches a certain threshold. Even then the recipient is responsible for paying gift taxes, not the giver.
The only time it would be considered income is if she's invoicing him directly and he's paying the invoices.