Sister in law pregnant too

Li

I just found out that my husband and I are expecting a baby in July. His oldest sister is also pregnant due in June. It's her second pregnancy and my first. I really want to announce at Christmas but I don't want to rain on her parade. I believe she is announcing at thanksgiving. I'm a little concerned that we will be compared during the whole pregnancy she is petite and I'm over weight. Does anyone have any advice?