F....35 year old tattle tails

Work should be about getting the job done, not what time you come in or leave. It's kinda nice working in IT. Our meetings don't start before 10 am and no one ever calls a meeting that starts after 3 o'clock.

I wouldn't worry about the whole thing unless your boss is a total prick, in which case you're probably better off seeking another opportunity.

The best thing to do is to not acknowledge it. Go to work, read the email, do your job.. and a few weeks down the road it will be forgotten and you can slip out early again.
If you go in guns blazing or even give any power to this, you will give it life and legs. Let it go and realize that this woman must be in a lot of personal pain.