Well that’s good. I mean, not that you had a raging fight, but that she realizes “WTF was I thinking?!” is the only right answer here. The OP made it sound like you raised objections and she was lalalalaing them away.
Glad you talked it out, sorry it took a fight, and here’s hoping the two of you get away TOGETHER very soon. Grandma will love the extra time with the baby - or at least she better pretend to!