Kes' father died when Kes was 1.
Kes' mother gave birth to Kes when she was 3.
Kes' father was 7 when he knocked up Kes' mum, and 8 when she was born... Adjusting for shorter gestation periods of course, so dad could have been knocked up the mother, raised the daughter, and then died all during his 8th year of life.
If we assume that this is normal.
It's easy for a female Ocampa to mate for life if her husband is already on the verge of death when she meets him.
Kes dating, bonding, and mating with men who will oh so very easily outlive her must upend her biological clock entirely, that between the ages of 4 and nine by her Ocampan assumptions, women should get to put their feet up on their husbands tombstone and tell their children that they better be mighty careful about thinking that they have any yen for babysitting at this late stage in their development... Which clearly now a fraudulent lifeplan.