Form AN - name at birth problem.

Can anyone please help with filling out question 1.7 and if it's going to be a problem.

It asks for the name at birth.
For all the visa applications like FLR(M) and IRL I have just been entering my married name and leaving the section for other names blank.
My married surname is who I have been known by in this country, it's the name my first passport is in.

Would it be a problem if I wrote down and mentioned my birth name (maiden) now, it specifically asks for it. The only place that shows is on my birth certificate and that has never been asked for.

I am just being an idiot. I am also filling in the child benefit form and that asks for maiden name, not sure if I should enter it there as it does not show on other Government records.

Would it be a problem if I wrote down and mentioned my birth name (maiden) now, it specifically asks for it.

Not an issue, simply complete the form as asked. You are over thinking.

Anyone know if you are required to show document proof of your maiden/birth name, before it is printed on the Naturalisation certificate? Or do they take your word for it?

My name on the marriage certificate is listed as my married name, that's how it was done for me.

No need to prove birth/maiden name. Your certificate will show the current name you have declared.