Why?!!!

I feel that I am being punished, I just found out over the weekend that my baby sister is pregnant with her second child. I cannot be happy for because she is a terrible mother, she neglects her child and she never has time for him but now she is having a second child and expects me to be happy. Don't get me wrong, it's not because I am struggling, it's because she cannot take of her one child who is 2 years old now, she is lazy and is a stay at home mom. She doesn't like the responsibility of being a mother but she is having another baby. Where is the justice in all this, so she and her husband comes over to our place on saturday and expects us to celebrate this with them. Really could you have not thought that this is not a good time for us. No, because that ever matters is her. I know my turn will come but why does it come so easy to others.