Is this considered menopause?

My mom used to be the MOST patient/relaxed/happiest/carefree person I've EVER knew. But a couple weeks ago she said she had a couple hot flashes. BUT she didn't act mean or do anything .. she just acted like herself. Nothing happened as the weeks went on.. but all of a sudden she flipped. To a mean/non-caring/non-talkative/yelling person. She has been like this for a couple days now and it's weird. She never wants to talk anymore. She'll sit in a room by herself and be perfectly fine with it.. actually happier about it. This isn't like her at all. When we normally get into fights she gets over it the next day but not anymore. Do you think she's hit the full menopause stage now or what? I actually feel horrible staying here.. Like unwanted with how she acts towards me. Sorry this is so long. And thanks ahead of time!