I’m Worried; My Wife Has A Lump In Her Bre*st

This is from a worried husband:
I just got newly married and found out that there is a round, hard stuff in one of my wife’s bre*st. I asked her about it, she said it happened when she was 15yrs (now she is 23). Back then she told her mum about it and her mum said it was a normal thing, that it will soon go.
She waited for many years it was still there, instead of going it was increasing and her parent refused to do anything about it.
She said she went to hospital on her own, after a doctor examine her he said it was not cancer because cancer does not move but hers does, that it was just a lump.
Now me worry is that, she is pregnant and I don’t want a situation where she won’t be able to bre*st feed our babies. My wife is pregnant with twins.
Please I need realistic suggestions on how to go about this issue.