Aggravated with my family!

Amber
So my husband and I have decided that we are going to name our 2nd daughter Amiyah Grace to go along with her older sister Ariana Elizabeth. Well, my mother and grandmother have decided that they're going to call her "baby Gracie" because they cannot remember Amiyah or how to spell it! (Their words - not mine.) They said they are just now getting used to Ariana's name (she's 2 1/2) and it will just be "easier" for them to remember "Gracie." This may seem petty to some, but I am really aggravated by this. My husband and I believe your name is what you should be called by, not your middle name, not some shortened version of your name, etc. We worked on picking out her name for quite a while, and this is really bothering me. How should I handle this? Am I over reacting? (I am 9 1/2 months pregnant.) Should we just change her middle name? She will be here in 9 days, and my family is showing no signs of cooperating. Advice please.