The Charlotte family is the family that Jill comes from.
The earliest known Charlotte is "Helena Charlotte." She was the mother of Edward Charlotte. One day in the 1960's, Helena got extremely sick so Edward and his wife Barbara Jill Charlotte founded "Jill's Hamburger Palace" to help them raise money for Helena.
Afterwards, Helena was in good health. Barbara and Edward's cooking was so good it turned into a family business. Edward and Barbara gave birth to Joshua, who took over when he was old enough.
Joshua got married to Jacqueline, and they had 2 children, Jill and Jordan. They are the great grandchildren of Helena, and it is unknown who will take over the business. It's possible that Jordan will, since he is the only son in the family, and Jill doesn't seem to be interested in the restaurant.