What happens when 3 people are on a will for a house? My mother got a equity loan on the house, so the other 2 signed a paper so it could be under her

The facts are not clear from your inquiry. Apparently three people own title to the house, and two of them consented to allow the third to obtain a loan secured by the interest of all three of them in the house -- is that correct? If so, then, if she dies, only her interest in the house will pass as she directs; the other two owners will continue to own it. If that is not correct and the entire ownership rests with one person, then her will will pass the entire interest as she directs.