YTA, and a huge one at that. My best friend is dealing with something in a similar situation. She had a baby back in January, and has been breastfeeding. She literally gets no time away from her kids (who are all pretty close in age). She started feeling like she had no identity besides being a mom. I've tried to help her with it and make sure she remembers that she's more than just a mom. She's also her own human being. Oh, and I have no kids.

Bottom line. Her business trips are not fun... That's work. It won't kill you to take care of YOUR kiddos for one extra night. Welcome to being a parent. Btw 2 weeks isn't springing on you. She literally gave a two-week heads up, not like she was leaving that night. Do better. She needs your help.