First of all, congratulations on your pg hun!

Second of all, I am so sorry you are going through such a stressful time with your family, especially your sister. You have done nothing wrong hun, your baby is very much wanted and your beautiful pg should receive as much excitement as your other two. Your sister's loss would be simply devastating, and she simply wants what you have. She is hurt, angry, jealous, irrational, and taking all her hurt on you. You don't deserve that, but to her it should be her that's pg. Not you, you already have 2. I don't have a sister so I can't speak from experience, but when I lost my little boy at 21 weeks, I cringed ever time I saw a pg lady. I lost Josh in October 2008, and then had corrective surgery in January 2009, so didn't come back to work after xmas until February. In my office a girl I know well had her IVF treatment when I was having corrective surgery and because she had complications with her cycle, she stayed away from work until April, even though she did get pg. Being around her was soooooo hard. But in the end I realised that I will be pg too one day and I turned my thinking around and was happy and supportive of her through her pg. I did get pg a few months later and we were actuall pg together. All the hurt, and anger and jealousy just went away when I became pg.