The Girl Who Couldn't Grow Up (1917)

Peggy Brockman's idyllic life with her oil-magnate father is disrupted when he remarries and arrives home with his bride and her two snobbish daughters. The new Mrs. Brockman reads that Lord George Raleigh is anchored off shore in his yacht, and regarding him as a possible conquest for one of her daughters, issues him an invitation to a garden party. In quest of his seclusion, his Lordship sends his butler Wiggins to attend in his place. Peggy is banned from the party, and in revenge, sneaks aboard the yacht where she meets the real lord who is enchanted by her. For her prank, Peggy is banished to college and the lord enrolls also. One night by mistake, Peggy climbs into the boys' dormitory and finds herself in Raleigh's room. To prevent a scandal, they elope, but on the way from the justice's house are arrested and thrown in jail. Peggy's horrified family arrives just in time to witness Lord Raleigh disclose his true identity and announce that Peggy is his bride.