Writer's Fallout Shelter

I have noticed a lot of people are very picky about punctuation in reviews. I have had some of mine corrected that are correct. I teach English, but I never trust what I think when I get a review like that. I run a search and read several places. "When" in your example is a coordinating conjunction even when it comes first in the sentence. You do need a comma after "born" because that is a dependent clause that come before the independent one.
Good Luck! My view is punctuation is low on the list of what should be reviewed unless it stands in the way of understanding.