Hi, Angela! I nearly cried reading your post! You are among friends here.
How old are your little ones? I'm almost 44 years old, and my youngest is 5. He's one of the biggest supporters I've got, even with all the other members of our family enjoying this new way of life. This evening he walked up to me, my waist at his eye level, and he said, "Mom, you're shrinking!" I said, "I'm shrinking, huh? Does this mean when I get too short to push the shopping cart in the store you'll put me in the seat and push it yourself?" He said, "No! You're shrinking this way!" and put his hands along the sides of my waist.
You know, even though your sister is in denial, you could be a great inspiration for her. I have three sisters, all overweight, and an overweight niece, too. Within two weeks, one of my sisters saw the huge change in me and started Atkins herself. Another sister has a lot of serious health issues, and I'm sure LCing would help her a lot (she's diabetic and has other problems too), so I sent her the link to Dr. Bernstein's website (LC specially for diabetics). I don't know if she's thinking hard about it just yet, but I know she's thinking about it.
My only regret is that I didn't start this sooner!
Best of luck to you! You'll find lots of support and friendly folks here!