Mac's tatoo...

If you haven't seen it yet and have wondered what the tatoo looks like that JZB hid under Mac's hair, here's the official design

Epiphany or nonsense?

I just had an epiphany! Or maybe only a silly idea?
I was just going through the next pages of  Bloodfever and re-read the dialogue between Mac and Barrons outside the graveyard where she is going to look for hidden OOP's. He tells her about the history of the sidhe-seers...

"So this Grand Mistress, she ran things?"
He nodded.
"Is there still one today?"
"One would expect the bloodline that directed the sidhe-seers for millennia to have maintained the lore."
That was on evasive answer I wasn't willing to accept. "What does that mean? Do you or don't you know if there is one, and if so, who is she?"
He shrugged. "If there is one, her identity is tightly guarded."

Mac must be the missing Grand Mistress of the sidhe-seers, resp. the Haven! Barrons knows of Rowena and does not think of her as the Grand Mistress. She is only the "witch" leading them at the moment. Also it would explain, why Rowena hates Mac. Something ugly happened before her mother left Ireland and fled with her babies to the States. I'm sure Rowena knows, that it's Mac that should be leading the sidhe-seers.

Also, Barrons is convinced, and tries to convince his "men"repeatedly, that Mac is the one they've waited for to do something special.  This something is not only to find the Sinsar Dubh. There is more to be done then. Maybe something only the Grand Mistress of the sidhe-seers can do? Contain the book?

And why is Mac's father never mentioned? If her mother was Grand Mistress at that time, and was at that time responsible for the containment of the Sinsar Dubh, what happened? How was it freed? Did her father play a role in it? Her mother must have had a relationship with somebody "special"? And why did Barrons not know, that the book was contained at the abbey? He has been looking for it for ages if not aeons!