What are other reasons certain older people get married?

Anonymous
In 2017, my manager got married at the age of 39 but she already had two children; a 20 year-old daughter and a 16 year-old boy at the time. The guy she married was 50 at the time and also had kids of his own from a previous marriage.

If they already have kids (and aren't having more), are much older... why get married? Is there a point by then?
Updates
1 y
What other reasons can there be to be marrying at such a late age if you're not having kids anymore?
What are other reasons certain older people get married?
2 Opinion