Hello Danette.
The maternal grandparents of James William Ferrell were William J Willoughby and Minnie LLoyd. It was his great-grandmother the one with the surmame Cox.
William J Willoughby was the son of John Henry Willoughby and Missouri Martha Cox. According to the following death record, William J was born in Chambers Co., AL on 25 Mar 1877 and died in Birmingham, Jefferson Co., AL on 8 Feb 1948:
https://www.familysearch.org/ark:/61903/1:1:J692-2J4
William J and Minnie got married in Jefferson Co., AL on 2 Sep 1908:
https://www.familysearch.org/ark:/61903/1:1:QKZS-WMGT
They were living in Daviston, Tallapoosa Co., AL on 1920. Myrtle was 7:
https://www.familysearch.org/ark:/61903/1:1:MXDR-89X
They were back to Birmingham on 1930. Myrtle was 17:
https://www.familysearch.org/ark:/61903/1:1:32BQ-WZM
Myrtle married Vincent Favata. They had two daughters, Mary Angela and Carol Jean, both of them died as a young children:
Angela: https://www.familysearch.org/ark:/61903/1:1:J69K-WPY
Carol: https://www.familysearch.org/ark:/61903/1:1:J6SR-7M1
Vincent (35) and Myrtle (27) were living with Myrtle's parents (Wm J and Minnie) in Birmingham on 1940. They are listed at the bottom of the following image:
https://www.familysearch.org/ark:/61903/3:1:3QS7-L9MT-99RK?i=4&cc=2000219
At the top of image 6 of 22 you will find your James Ferrell. He was 4.
(According to the 1940 US Census, Myrtle was living in Detroit, MI on 1935. I think this is important to search for the father of James)
Myrtle died in San Mateo Co., CA on Sep 25 1997 according to the following record:
https://www.familysearch.org/ark:/61903/1:1:VP8F-YW1
Hope the information above helps in your search.