Hmmmmmmmm I am thinking just maybe there could be more to this. Did she not want to buy the house you were in but you kept pushing for it? Like did she cave in and just do it even though she wasn't happy?

It sounds like this is something the two of you have disagreed on in the past. I agree her tantrum is like a 2 year old. But could it be possible she is doing something drastic because she hasn't been listened to any other way?