Identifying a Porcelain Doll?

This doll belonged to my mother-in-law's mother. It is from the late 1800s she's guessing, she first saw it in the 1930s. The doll has a marking that looks like a "t" on the back of the neck, on her arms it looks like a "P309", her clothing is hand sewn, her arms and legs move, her eyes open and close, her head does not move, and the entire doll is some kind of porcelain.