Child Birth and 401K Roth Hardship

I have a child due later this year and my employer doesn't offer any sort of paid maternity leave or short-term disability, I am allowed to do a hardship from my Roth 401K without penalty according to ADP.

 

What sort of documents would be needed to show proof of birth, for tax purposes or for an audit?

What are the requirements specifically for birth of a child hardship?

Are they the same as every other hardship? 

If my Roth has already been taxed, will I be taxed again on the hardship withdrawal?