Why is the emotional immaturity so triggering?

The stuff that sets me off the easiest is always the little things. It’s how she says things, the words she uses, the approach she takes. She just shared some bad news and instead of saying “this is what happened” it was as if her text to me was someone’s Facebook post and she was commenting. Basically the most indirect and backward way of letting me infer something happened without telling me, and I am reeling.

Right now the bad news isn’t even what’s getting me. It’s wondering why she can just communicate like a normal adult with her children and never will.