Help please

[Duchess]

I have a few birth certificates and on three of them it has the mothers name as the informant showing she could write
and then on the last childs birth certificate it has the mark of her name, the last child died the same year, and on the death the mother is the informant and it just has her name and not the mark of.
She was 37 when her last child was born, could she have been ill or something to suddenly not be able to write her own name?

[Waitabit]

Duchess, I've had a similar case re a marriage entry where the bride did not sign but shortly after wrote a longish letter to a Nephew.

Ever hurt your hand & not been able to write? That's the thought I'm clinging to.

[Guy Etchells]

It is not uncommon for literate people to make a mark on official documents when told to do so.
When I was at school in the early 1960s there was an instance when as cadets we had to sign the Official Secrets Act, a number of the boys made their mark rather than signing because that is what the officer told them to do.
All were fluent writers.

Remember society was more authoritive in the past and people tended to do as they were told.
If one was told to sign his/her name they would sign; however if they were told to make their mark they would make their mark.
Cheers
Guy