Almost told my mom....

We are doing a for sure announcement on Easter, but I wanted to give my mom a heads up 1st cuz with my last baby she told me she would have been pist if I didn't tell her b4 my SO's mom. I wanted to tell her today but I couldn't get up the courage. We were talking about 3 of my cousins being pregnant and all having boys and I just couldn't find the words. I think I'm going to get a onsie for my 7mth old and write "I'm going to be a big sister" on it and hand her to my mom. No turning back when I go to visit and she's wearing that. What's the worst that can happen?!?!