Sister Jealousy

Sarah • 23 years old married with one three year old daughter and a newborn son
Ok so my sister is now 30 and she hasn't had a child of her own. Doctors say she will never have children. I can't help but feel like my sister is either envious or hates me. She and I have always been close but when I told her the news she was not happy at all. Now I'm scared to show family updates on the growth of the child for fear of upsetting her further. 
Any advice?