My sister and my pregnancy help!!

My older sister has been trying to have a baby for about 4 years with no luck (she has PCOS and is getting help from a doctor). I think she is amazing for being so patient and not giving up.

My husband and I decided to start trying for our first this past February. We were extremely lucky and got pregnant on our first cycle of trying. While I know my sister is happy for me I see how sad she is and I feel so terrible and guilty. I feel like I shouldn’t talk about my pregnancy even though she says she wants to hear about it. I don’t know how to act around her and enjoy this with her? (She is my only sister and we are very close.) has anyone been in a similar situation? Is there anything I can do to make this easier?