I think I have found a biological solution to prevent menopause. My Kepler Bb humanoids don't get more frail with old age so aging is not a cause of death for them. They can survive well past 100 years if the conditions are just right. Because of this, I figured "If they don't die of old age, what is the point of menopause?"
This led me to my biological solution that involves adding differences to human anatomy.
In particular, there are 2 pairs of ovaries connected by small tubes. These are the primary and secondary ovaries.
The primary ovaries are closest to the fallopian tubes and are where meiosis takes place. Once meiosis is complete and thus the egg is haploid, ovulation takes place.
The secondary ovaries are closer to the uterus and are where mitosis takes place. Oogonia are like stem cells here. 1 becomes the next oogonium while the other becomes an egg cell. This primary oocyte that results from mitosis migrates into the primary ovaries where a follicle starts forming around the oocyte.
The only way menopause can happen in these females is if the secondary ovaries are surgically removed or become dysfunctional and stop producing eggs. Otherwise, the female will continue ovulating every month until death.
But is my biological solution plausible? I mean yes, lifetime ovulation does mean higher chance of pregnancy mortality and ovarian cancer. But considering that these humanoids don't die of old age, is it a good solution?