Looking for the Volk Connection

This name appears as long ago as my great-great grandmother Mary E. Volk Draper, I've seen it also attached to my great grandmother Edna Mary Volk Reynolds. But, Mary E. Volk Draper's father is just Draper. My theory is she is adopted and kept this name "Volk", but I can't make a connection anywhere. I believe "Volk" is a Germanic name, I'm not sure. Mary E. Volk Draper was born in London about 1866, migrated to Canada, I think with her family, married William Class in 1885, and they eventually migrated to Michigan and on to Washington state where they are buried. any information would be greatly appreciated. Thank you.