Perimenopause question?

My mom has been going through perimenopause, which apparently is the period right before your last menstrual cycle. Well, she has been bleeding now for 26 days straight and feeling really weak and dizzy due to this. She thinks that it is just her last period ever, but I saw her today and she looks really pale. I am worried she has developed anemia due to the blood loss. She just isn't herself and it's scary. Does anyone know if this is normal to bleed this long for your last period before menopause?