1530s, typical name for an English woman of the lower class, hence "girl, lass, sweetheart," sometimes also "strumpet," from the pet form of Isabel. Often paired with Tom, as Jill was with Jack.
Examples from the Web for tib
Historical Examples of tib
The boys will care for this raree-show more than thou or I, Tib!The Armourer's Prentices
Charlotte M. Yonge
Smith at Tib I v 70 gives numerous instances of both images.
Then he ran forward, with Tib dancing and yelping round him.
Tib was a puppy that had been given to Jamie by one of his new acquaintances.
Sap her a top o reeb and a tib of occabot, is only, Hi, boy!The Criminal