How do I tell my sister.

Long story short. I'm pregnant and kinda scared to tell my older sister cause I don't want to hurt her feelings. After her marriage she and her husband started <a href="">IVF</a> (cause she had cancer and carries the gene). Unfortunately the marriage did not work out and she is now a single 36 year old without children. I know the wants children, but she is very traditional so she will never choose to have them on her own. So now she is a little bit depressed and scared that she will never have kids. How do I to tell her that I'm pregnant. I feel like I have so much more luck in my life than she has and I don't want to point that out. I do want to make it a special announcement, but I do not know how she will react.