Winter - who plays Alex Dunphy in the ABC comedy - was removed from her mother's care by the Department of Children and Family Services earlier this week after allegations that she had been subject to physical and emotional abuse.
The 14-year-old is currently staying with her sister Shanelle Gray, who was herself removed from her mother's custody 20 years ago.
However, Winter's brother Jimmy Workman has now told Us Weekly that there is no basis to the allegations against Chrisoula 'Crystal' Workman.
"There is no truth to these allegations," he said. "The allegations made 20 years ago are not true and the ones today are not true."
Workman continued: "This is a mother who does everything for her kids... Chris misses Ariel and wants her to come home."
Chrisoula Workman has also denied the allegations, insisting that she has proof that no abuse has taken place.
The next hearing in the case is currently scheduled to take place on November 20.