I went on a killing spree and entered Jorrvaskr to kill the companions. I hit Tilma with a fork and she started attacking me. I then put my fork away and she put her dagger away. I press activate on Tilma and she said "You fight well Sister."

Tilma is Badass.

That's funny. I would have never thought her to have that dialog.

I suspect she has seen her days of action. Granted those days were no doubt around the time of the Dwemers, but still...

The Silver Hand will feel the strength of her broom.

Never underestimate an old lady with a broom.

I should know that first hand.

I never believed her "I'm just a servant dear" routine.

I think she is far older than she looks.

If you read the book Great Harbingers, you will find the tale of Macke of the Piercing Eyes, who inexplicably dissapeared, or did she simply, eventually, hide in plain sight?