[Calvinist_Dark_Lord]

But she still forgot to tell that Brother Nevil was a cylon.

With due acknowledgement to RandallFlagg, the character is named Brother Cavil, and Dean Stockwell is doing an excellent job, well worth the cost of the actor. That was written as a choice that Sharon made out of her grief over the child that she believed to have been murdered by the powers-that-be.

This was either a plot hole, or an interesting question that bears investigation:

i don't know if you have children or not, but what mother EVER forgets the features of her newborn infant? Now in this story we're dealing with a Cylon, who can never forget details. Sharon saw a dead baby, and ASSUMED that it was her child. It was not a decision that a Cylon would make. It was a decision where fact was clouded by emotion. A human mistake.

[RandallFlagg]

There was one interesting thing Sharon/Athena said, though: "But this Cylon will keep her word, even if it means she's the last Cylon in the universe. Can a human being do that?"

Interesting that they'd pull out the, "LTCDR Data," line.