Barbara Starrett was a librarian at Derry library. She is a kind and caring woman who has a special spot for Ben Hanscom due to his polite manners and the fact that he gets bullied a lot. Ben also has a mild crush on her and also liked her a lot. She dies of a stroke in 1982, which upsets Ben as an adult. Although it might be just It tormenting Ben, the stroke could have been caused by Pennywise after It reveals on a balloon that It killed her.
She does not appear in the 1990 miniseries but appears in the 2017 adaptation, although her personality is completely changed, appearing to be a grumpy, mean old woman who criticises Ben for reading books during summer and says he should be outside playing with friends and then cruelly asks him if he has any friends.