Posting because I’m wondering if anyone else’s child has gone through it.

My daughter is 21 months old. We breastfed until she was around 15 months old. During that time she had little lumps under her breast due to the hormones. Well, it’s been 6 months since she’s last breastfed and still has a lump under in right breast. She doesn’t have one in the other. It’s soft and moveable, and her doctors said she isn’t concerned about it but has ordered and ultrasound on it anyway. Did anyone else’s child have this issue too?