MIL laughed about baby name we picked 😒

We had planned to name our baby Ariella if it were a girl pronounced like air-ee-ella. We thought it was a cute name and we could have the choice of either calling the baby Ariel or Ella for short if we thought it fit the baby. Well we just found out today that it was a girl so when his mom called me today about the baby she asked about the name and I told her. She started laughing and said she already knew because my step-daughter who is four (so has trouble with pronunciations) I guess said it to her aunt when she was over there one day. My MIL said her and her daughter, the one that knew the name already, were laughing about it because it sounded like areola like the part of the nipple 🙄 so she just went on about how the baby was gonna be called that by other kids and I started getting mad and saying that's a weird thing to say and to even think of and why even say that. She was just like I don't know that's what I thought of when I heard the name.