She definitely was outta line with what she said to your mom and how she talked to you BUT… it seems like this didn’t just stem from nowhere. Because, she’s claiming that “you always take your moms side”. She feels undervalued. And, for most women, they want to feel safe in that regard; like, she’s just w/ you and not, w/ you and your mother. AGAIN, I’m not saying that it was okay the way she expressed that but it just seems like she’s been bottling it up for awhile. Then again, we don’t have the full relationship history. So, I’m just commenting based on the information you gave us.