As it turns out, of all the personified traits in the play, Good Deeds is the only one capable of guiding Everyman to his final judgement. Good Deeds is also the only one who remains with Everyman until the last, and speaks in his defense. In this manner, Good Deeds represents the sympathetic side of human nature, and the common personification of love, empathy, and altruism as female; the "mother" aspect of femininity echoes this interpretation as well.
Good Deeds: All earthly things are but vanity.
Beauty, Strength and Discretion do man forsake,
Foolish friends and kinsmen that fair spake,
All flee away save Good Deeds, and that am I!
(Anonymous, Everyman, eNotes eText)
As all of Man's achievements fade with age and time, only his deeds -- hopefully good -- are left to commemorate his passing. In the same manner, Man cannot reproduce without Woman, and so Good Deeds symbolizes both procreation and commemoration. Man's actions -- his deeds -- and his children -- borne by Woman -- are his lasting legacy, and so the two are inextricably linked; without Good Deeds to "speak" in Everyman's defense, there would be nothing to remember except the Sins that initially weighed her down.