The two central characters in "Briar Rose" are Rebecca Berlin and her grandmother on her mother's side, Gemma. The other three seem to be Magda Bronski, Father Stashu and Josef Potocki, but there is one more, Stan, Becca's love interest.
"Becca's true emotional support is Stan, her editor at the Advocate, an alternative newspaper."
"Better developed are the characters in Poland, who underscore issues of unresolved guilt and national devastation. Father Stashu shows Becca the Chelmno Schloss, the old castle the Nazis used, and explains that the abrupt, reticent behavior of the city's men today results from fear and guilt. Magda Bronski is Becca's cheerful interpreter and guide, contacted through an American university's Polish Jewish program.'
"Josef Potocki, Father Stashu's elderly friend. Josef is the person whose initials JMP appear on Gemma's ring, the key to Gemma's past, and a key storyteller in the novel's later pages. He is a shockingly revised characterization of a fairy-tale prince."