HaBO: Heroine Gives Her Wig to Another Woman

This HaBO request is from Courtney, who is hoping to find this historical romance:

I’ve been searching for a Regency romance that I bought in 2003/2004 at Wal-Mart. It starts with the heroine at her first ball and drinking champagne for the first time. She has too much and goes to rest in a front room. The hero comes in and thinks she’s a courtesan. She lets him know that she’s not.

Another scene is heroine is blonde, but has a white wig on. While going into a ball, the wig is blown off a brunette girl near the heroine. Since the heroine doesn’t want to wear her wig, she gives it to the girl, who becomes her best friend and is prominent in society. The heroine’s dad ends up having an affair with the brunette girl’s mom.

Two titled men make a bet on who can bed the heroine or her blonde sister first. The heroine’s dad is in debt (from gambling) to one of the men, so the heroine has to marry him to clear the debt. She has already lost her virginity and gotten pregnant from the hero, so she cuts herself with a ring to put blood on the sheets to fake her virginity. Her husband thinks it’s his son. The husband dies, and the heroine marries the hero (has a higher title than the previous husband I think). The hero then finds out that the baby is his.

Any help is appreciated. I’ve been driving myself crazy for years trying to find this book.

Whoa, there is a lot going on here.