I like how by the end she has him serious about college, wrapped around her finger, and willing to take responsibility for his child – even if only those two know it’s his.

Biology note: a woman has her menstrual cycle from when they hit that point in development (12-13 is common) until they hit menopause (and their body is out of egg cells), usually around middle age (mid 40s to late 40s/early 50s). Their fertility doesn’t decline very much (until dropping to 0), though the quality does decline – greater likelihood of slight issues or genetic things, if memory serves. Maybe also greater chance of miscarriage. But not too bad overall. It’s because they have some large number X egg cells sitting there maturing, a number set at or by birth, whereas us dudes are constantly producing sperm cells, at least once we’re old enough.
…Nature is really impressive.