What is the most logical next event?

How to convince someone to spay or neuter their cat
Emphasize the health benefits.
Spaying their cat will significantly increase its chances of living a long life, with fewer health complications. A cat that has not been spayed is significantly more likely to suffer from uterine infections and breast cancer, both of which are deadly in a majority of cases.
Explain to the owner that it will them get a better night's sleep. A female cat will go into heat four to five days every three weeks, making nearly a third of the time the owner spends with their cat hellish.