Can we claim the interest on a property a family member owns if they died and we have been paying the mortgage, taxes, insurance, and repairs?

Another family member is living there who is also not the legal owner. But we pay every expense associated with the home. Mortgage, taxes, insurance, repairs, and every single utility bill. The home is listed as "estate of" until we complete probate but we have personally been paying for everything since the family member/owner passed over a year ago.