A slightly weird set of numbers here. Perhaps just a slightly weird interpretation. Talking about step-children, divorce, children and the length of time a relationship lasts:

Having children with a previous partner does not affect the stability
of a woman’s future relationships, Government-funded research shows.

Now that is interesting…although I’d be interested to see if it has any effect on the formation of a new relationship. But this:

Married parents with young children are less likely to
divorce. Having one pre-school child together makes them 40 per cent
less likely to separate than couples without children. This is reduced
by a further 38 per cent if they have two or more young children.

The
odds of cohabiting couples separating are reduced by 25 per cent with
one pre-school child and a further 44 per cent with two or more.

But the stabilising effect of children weakens as they become older.

I’d pretty much call that a "No, Duh?" finding. Having young children tends to come near the beginning of a relationship…..not month one obviously, but not often in year 20 either. So the presence of young children is, to an extent, an indicator of the age of the relationship and obviously, the break up rate increases with the age of such.

So not a very surprising discovery.