OFH references Heavenly Mother in his popular Gospel Themes book.
Orson F. Whitney, Gospel Themes: A Treatise on Salient Features of “Mormonism” (Salt Lake City, 1914), 65
Born of God.—To be "born of God" literally means to come forth from God. "Born of woman" has a like significance. We have a Father and a Mother in heaven, in whose image man was created, male and female. We came forth form them—were begotten and born of them in the spirit, as much so as we were afterwards begotten and born in the flesh; and we must be begotten and born again, in the similitude of those other begettings and births, or we cannot regain the presence of our eternal Father and Mother.