Can u win a small claims case if all mom has is daughters brothers and sisters as witnesses?

daughter gets loan for mom against her van in her name with a verbal agreement she made the payments mom makes the payments and then gives the daughter the balance in cash how can daughter prove the mom give her the balance in cash with the siblings going to small claims hearing to be witnesses against there sister she has paper work from the bank simply saying her van was the collateral whats the chance she daughter will win?