I believe Emma Magee-Johnson  (born in the late 1870's) was Crecy (Lucretia) Johnson-Magee's (born in 1854) Sister-In-Law.
Crecy (Lucretia) Johnson-Magee was a daughter of Josiah Johnson and Charlotte Sweat.
Thanks to Robert Moreland for providing this photo. Lucretia is Robert's Great Grandmother & Emma is Robert's Great Aunt.
Left to Right: Crecy (Lucretia) Johnson-Magee, Emma Magee-Johnson

Photo donated by Chuck Gassiott