Answer:

GREATAUNT

AnswerCrossword Clue
GREATAUNTWoman in a tree?
GREATAUNTFamily reunion attendee, maybe
GREATAUNTReunion attender
GREATAUNTSenior family tree member
GREATAUNTMatriarchal figure
GREATAUNTSocial reformer Margaret Fuller, to Buckminster Fuller