She might - but she might not. Unless you are a doctor I would resist diagnosing her, however you could ask her if she’s feeling ok and whether she might want to see a professional.
Can people suggest tactful ways of suggesting to dil she might be in v early stage of menopause? I get on well with her and something she is doing is a bit extreme and out of character. On top of that she has recently started a new job and I would not want that affected. Can you go straight onto HRT this early? I never did that myself.