The Miller was the father of Coignice (she was known as the miller's daughter), and grandfather of Valanice. This is much the same as the girl in the tale of Rumplestiltskin (and it is possible they may be the same individual).
There once was a miller who had a beautiful daughter--a daughter so beautiful that he pridefully thought she should be the bride for the king (he may have been Prince Cedric at the time). One day the miller was delivering flour to the castle and, noticing the king nearby, began to to boast about his daughter. The king listened politely, but everyone tells kings that their daughters are the fairest in the universe. "Ah," invented the miller, "but my daughter can spin straw into gold!" Now this got the monarch's attention, and he commanded that the girl be brought to him.
After a series of situations where the king threatened to kill the girl if she didn't spin straw into gold and with help of Rumplestiltskin, his daughter became queen of the land and also had a child (possibly Valanice, as the gender is not given).