I think you should take this opportunity to talk with your SIL (as a parent of your DC child
not as your SIL) and discuss with her what her expectations are in regard to her daughter. Gather some developmental information for the child's age group and talk openly with her mother about what she should and shouldn't be doing at this age.
Work together to set some goals and work toward accomplishing those goals. Give the mother some ideas and activities that she can do at home with her daughter. Don't allow a parent to make you the primary person responsible for educating their child. It is the parents responsibility to educate their child at this age and stage of her life.
At this age, she shold be learning social skills, self-help skills and just about herself in general. Academic come later and really shouldn't be part of her daily learning curriculum while in family child care and at 1 or 2 years of age.
Hang in there....we've all been there!
