I love my sister, but I will take her down

My sister and I have decided to battle each other with a weight loss challenge. It was her idea for us to lose 15 pounds before we head to Aruba in October. Now she suggested this in June, but she has just now decided to get serious :-) So, to keep both of us motivated I decided to put a wager on it. The sister that loses 15 pounds first is paid $100. She was in, so I started talking trash talk. I am confident I will win. A couple of days later, I sweeten the challenge to keep the loser (Stephanie) engaged in losing their 15 pounds. Stephanie would pay me $5 for every additional pound I lose until she reaches 15. As I said, I plan to win!!!

Periodically, I will post updates of our progress. My sister is competitive, so this should be interesting.

Post in the comments who do you think will win, Team Stephanie or Team Tanya.