Could my mom really be in menopause already at 45?

I thought that didn't happen till you were like in your 50s. She's got a twin sister who had a baby like a year and a half ago. They would get their menopause at the same time as each other, wouldn't they? I'm asking because I asked a question a few days ago about how my mom has been flipping out about everything that we do, going mental on my bro and hitting him with a ruler, and like being OCD about having our house messy while its being redone. She went to a good college and had a good job b4 we moved here and she's never been insane but she was always like more highstrung than other moms. She does get hot alot but we moved from Chicago to Australia 2 yrs ago and it is WAY hotter here so we've all been complaining about the heat. Idk if it is hot flashes.