Oh, I didn't make any claims. The reason I make up an arbitrary overspecified date for Jesus is just to draw out people who have other claims about it. But for Mary this is new info to me and so I have no claims, my MO is to list what I can be comfortable with and to give sources. I totally agree we don't know her birthday, and you may recall my recent Bible evidence that birthdays are pretty sketchy in the first place. For the conspirators, though, I like to indicate lines of evidence that might be fruitful.