Rai Grimm is the only daughter of Erica Grimm and the granddaughter of Grimm Corp's CEO, Trey Grimm. Rai was raised mainly by her nanny Athena and away from her mother - so she knows nothing about Erica or her father. Since she was young, her grandfather trained her hard and long in order to get her powers to work.
At some point in time with Athena's help, she ran away from home never ot be seen again. Including changing her appearance.