Jane is a bit of a jerk. She is the only midwife in the village, so this allows her to raise her service fees, because she has no competition. She is gouging her customers and there is nothing that they can do about it. Not exactly a glowing beacon of altruism there.
She isn't emotionless. That's clear because she is often angry at Beetle/Alyce. I would say that Jane is closer to stoic or "icy." The text says that she does her job "with energy . . . but without care, compassion, or joy." That lack of emotion doesn't make her "bad" or "evil." It makes her clinical. In a lot of ways, she resembles quite a few doctors and surgeons I have dealt with.
She is an intelligent woman. She has to be in order to know so much about being a midwife and the power of certain herbs.
She is not much of a giving woman either, because she frequently stunts Alyce's education by severely limiting what she is willing to teach Alyce.
Jane is short tempered because she can get made with Beetle/Alyce very quickly.
Jane is also Greedy she tries to get the Bailiff's wife to pay her even though Jane wasn't there to help, Alyce was.