Deductions & credits

My mother lives in a house that both her and my name are on the deed as joint owners. When we purchased the house, I put up 25% of the purchase price and my mom put up 75%. We now want to sell the house. I will actually receive 25% of the proceeds. Can I report only the 25% of total sales price as income or will I need to report 50% since we are co-owners?