Eighteen-year-old Merope has dull hair, pale face, and plain appearance, and her eyes are staring in opposite directions. Merope's father was extremely rough with her, and derisively called her a "squib" (among other unpleasant names). Harry thought he had never seen a more listless person than Merope. In addition to her shabby clothes, Merope also wore a gold locket that her father claimed had once belonged to Salazar Slytherin (Half-Blood Prince Chapter 10).
Merope is strongly attracted to Tom Riddle, a wealthy Muggle, but she encounters some problems. She knew that her father and brother would be staunchly opposed to her association with Muggles, and that Tom would view her as an object of ridicule and disgust. But after her brother and father were arrested, Merope used a love potion to get Riddle Sr. to marry her.
It is unknown why Merope let the love potion wear off after she became pregnant (probably because Merope stopped using the love potion on Riddle Sr.), and Tom Riddle abandoned her. Merope came to London and was so poor that she had to sell her priceless gold locket to Mr. Burke of Borgin-Bock store, and received only 10 Galleons. Later, on a snowy New Year's Eve, Merop gave birth to Voldemort in a Muggle orphanage and named him Tom Marvolo Riddle (Chapter 13 of Half-Blood Prince) before his death.