Definitely, it’s obviously not Fiske’s daughter; he didn’t have kids, as you said, and then he wouldn’t be her uncle, anyways.

Even though in Book Nine: Storm Warning, it says Nellie Gomez wasn’t born a Madrigal, she could still be a Cahill, and it’s definitely a possibility she was the daughter of Anne Cahill (Nella Chain).

I suspected NRR was a Madrigal since Book Five: The Black Circle (as did many others) because she didn’t seem to care that her branch lost the clue. As you say, that is certainly correct.

Beatrice may have been working with Grace more closely than they have said, but I highly doubt she did much; in Book Nine: Storm Warning, Fiske pretty much says Beatrice isn’t very involved.

Certainly could be a possibility. In fact, I’ve checked it with a bunch of different book character’s and Cahill’s. Unfortunately, I haven’t found anything.

The other possible relative is Anne Cahill. We do not know she was childless. She changed her name to Nella Chain and she knew Grace.

Did Hope know who Nella was? She might have named a child Nella/Nellie if she did. I suspect Nella is involved in any case.

BTW this means NRR is Madrigal because she is working with Fiske. Also, female case of hemophilia are 1. very rare and 2. not as severe as male.

Just to throw another thought out – while Beatrice has been maligned throughout, I am not certain she was not working closer with Grace than we have been led to believe.