Hi Cathy and Welcome,
I am a wee bit confused as to who and what you require help on, I am guessing you are looking into Powells. I have not followed the line of James and Mary Ann as they are not directly related to me. I do however have information on Sarah and Ellen as they married into my Farrells.
You say Patrick turns up on the 1920 census "living with the family". What family do you refer to ?
If you mean Anthony and Sarah, that is incorrect, Anthony and Sarah are listed in 1920 in West 53rd Street, Manhattan, New York with Mary, John and Anthony (their children). There is a Patrick & Ellen in the 1920 census but if it is the one I think it is, it is not them. Patrick Farrell (brother of Anthony) was supposed to leave for New York on the S.S. President Harding in November 1926 with his brother Peter (my Great Grandfather) but didn't. Patrick died in Motherwell in 1955 and the death that sancti kindly provided is Ellen Powell who died in 1963.
From your first post Patrick and Ellen stayed in Motherwell, that is correct and Anthony and Sarah went to the USA, and Sarah and Ellen's sister Bridget went as well. So as far as any of them staying in Motherwell, I only have information on Ellen.
Kind regards,
Liz