H who is a renowned doctor in the city and who is also the father of Q, has two cute grand-daugthers C and S. K got married a certain numbers of years ago and now has only two sons. R who is extremely chirpy is sister-in-law of I. C is not taller than S. R is shorter than three persons but taller than her daughters. When it comes to plucking grapes the males have an advantage of their heights over the females in the family. I is shorter than his brother and father. There are two married couples in the family. The one who is the eldest in the family is the tallest as well. S is not taller than her grandmother.

How is S related to I?