Records reflect Emeline Chatfield was adopted:
Emeline Chatfield was renamed Emma Winchester
Sep 5, 1882 Westfield, Hampden, MA (by adoption)
List of persons whose names have been changed in Massachusetts, 1780-1892; pg. 249 (findagrave.com on her mother's page)
The 1900 U.S. census for Westfield, Hampden County Massachusetts has Emma J. Winchester, born Dec. 1878 in Massachusetts, living with her presumed adoptive parents, Willian & Jesse Winchester.