TTC - Sister Announces Pregnant

My husband and I have openly been TTC for about 6 months with no luck.

My sister doesn't have regular periods, and has not been using protection for the last 4 years with no pregnancies so she assumed she would probably never have a baby. She just recently let me know that her and her boyfriend are 8weeks pregnant and I could not be happier for them!!

Is it selfish if my husband and I continue trying for a baby? I don't want it to seem like I'm trying to take away from her moment.

In case it matters, neither myself or my sister have ever been pregnant. I am 26, she is 31.

Any advice is appreciated!!!