Margaret Osbourne Musgrave is the sister of my maternal grandfather, Joseph Musgrave. I have gravestone evidence that she died on 11th May 1946 in the USA. I don't know when she first emigrated, but she seems to have returned to England in May 1939 and then returned to the USA in October 1939. I have been researching the Musgrave family tree for some time now and have information going back to 1665, if you are interested. Margaret's brother, Hesket, was living in Michigan in 1930, so there could be some connection there.
In the 1960's, I used to write to a relation in the USA. She was called Joan, but I'm afraid that's all I can remember. She should be in her fifties now.
Would love to have any information that you have about the family after 1930, as that is as recent as I have been able to trace.