There has been a lot of discussion on this. Overall, IMO, the consensus is not to judge without knowing their family dynamics. She texted to ask what's for dinner, mom said brats, she said OK and never showed up. It is debatable whether or not that constitutes confirming "plans". We also do not know if this was typical. Perhaps Mom makes dinner and kids show up later. Maybe even after she's asleep. Maybe it isn't formal dinner together. I find it impossible to know or judge without knowing their relationship dynamics. I am sure mom is looking back now and wishing she had followed up. But obviously at the time it wasn't concerning. I can't imagine her pain. JMO.