Two Northridge children who watched explicit sex scenes on a rented videotape that was supposed to contain only a Disney cartoon each will receive $4,750 in an out-of-court settlement. San Fernando Superior Court Judge Fred Rimerman approved the settlement reached after an attorney for Susan B. Sanders, whose children saw the videotape, threatened to sue Wherehouse Records, which rented the film, and Walt Disney Productions. The attorney, Jerry L. Webb, said Wherehouse and Disney agreed to share the settlement costs. But a Disney official said he was unaware of any settlement. According to court records, the children, ages 6 and 7, suffered from emotional trauma in February, 1985, after they viewed the videotape rented from a Wherehouse outlet in Northridge. Webb and Robert Block, attorney for Wherehouse, speculated that a previous renter might have added the material.