Sister midlife crisis? Needing advice..

Hello! So my sister is 34 years old.. she’s the oldest of me and my 3 sisters. We have all been a very close family, however, I feel that my sister is going through a midlife crisis or just a dark period right now and is masking it. She has always loved being with family.. she has 3 daughters, and then the rest of our family all live close and have a total of 7 kids. Over the past few years, she soends less and less time with family.. she is a photographer and is constantly overbooking shoots and when she is not doing shoots she is booking herself eyebrow appointments/hair appointments/going shopping for herself and her clients.. her daughters struggle with this and often cry because she will be gone literally all day most days. She is my daughters godmother and she has forgotten to get her gifts or do anything special for big events in her life, and I get that life happens sometimes and you forget, but this is just happening so often lately.. her marriage is a mess(they were doing couples therapy but they stopped due to covid), her children are struggling majorly (one has ADHD and has major behavior issues), she just got a puppy that she tried to rehome after only 4 days. It just seems that things are such a mess in her life and they are starting to affect the rest of the family.. however, if anyone confronts her about this and tries to check in with her or mention that she seems to be losing a part of herself, she immediately gets defensive and threatens to cut you out of her life.. any advice??