The "Sister, Sister" stars would regularly visit the "Full House" set when their brother, Tahj Mowry, appeared on the show.

Ashley and Mary-Kate Olsen as Michelle Tanner in 'Full House'. Bob D'Amico/Disney General Entertainment Content/Getty. According to the Los Angeles Times, when the twins were 6 months old, ...

Mary-Kate and Ashley missed the high school dance to co-host "Saturday Night Live" in 2004. Fallon and Forte graciously served as their dates in a prom-themed sketch. quicklist: 6title: 6.