The doting and concerned mother of the three Epanchin sisters, Mrs. Epanchin worries both about her daughters' need to get married, and also about the fact that their family seems to always be a little off. She takes Myshkin under her wing from pity but is unsure if she wants him to marry into the family.
We're going to go ahead and make a sweeping generalization about this novel. Now, don't get any ideas here—we can do this because we're Shmooptastic, and because these character summaries are so super-short, but if you're writing an essay, then no generalizations for you, friend.
So, anyway, where were we? Oh, yes, big and sweeping. The characters in The Idiot can be broken down into two categories: innocence/naivety and experience/jadedness. Usually, the division make sense—everyone who's fresh and new to the world tends to look around wide-eyed and believing (think Myshkin, Kolya, or Aglaya), while everyone who's been around the block a few times has become at least a little cynical about life's vagaries—like say Nastasya, Varya, Keller, or Lebedev. But in the case of Mrs. Epanchin, we are constantly being told that she is just like a child—usually by Myshkin, for whom this is pretty much the highest compliment that he could give. So what is it about her that makes her "a child"? Which of her actions are childish? In what way?