Heartbroken.

I'm really offended. Maybe I shouldn't be.. 
Last year I had a miscarriage a week before my sister gave birth to her first baby. I was 16 weeks with twins and lost them. Obviously you can imagine how heartbroken I was, especially with my sister having a newborn around all the time which understandably made me jealous. 
Now I am 21 weeks with my baby boy and everything is going great which I am so grateful for! My sister has just told me she is 11 weeks. She said she didn't want to tell me because she didn't want to "steal my thunder". 
I am so heartbroken that after everything that I had to go through, keeping a smile on my face while seeing her in hospital etc when all I wanted to do was break down in tears as I didn't understand why I wasn't able to have my children but she was, hers. 
Now just roughly 10 weeks after I give birth to my rainbow baby all the attention will be on her and her new baby and how she has the perfect family. 
The worst part is, I'm not as close to my mum as she is and me being pregnant has started a different kind of bond between us which I feel is threatened now as they have a much stronger relationship that my mum and I. 
Maybe I'm just jealous.. I really feel hurt.