Doctrine and Covenants 121: 26-28
26 God shall give unto you knowledge by his Holy Spirit, yea, by the unspeakable gift of the Holy Ghost, that has not been revealed since the world was until now;
27 Which our forefathers have awaited with anxious expectation to be revealed in the last times, which their minds were pointed to by the angels, as held in reserve for the fulness of their glory;
28 A time to come in the which nothing shall be withheld, whether there be one God or many gods, they shall be manifest.
The only accepted, revealed truth about Heavenly Mother is that she exists. Its also pretty evident, when one studies the doctrine and thinks logically about how God came to be that there are many gods. And that's pretty much all we know. Who they are, the divine being who like our ancestors have come before us, is still not revealed.
I'm certainly one of those who have been waiting with "anxious anticipation." This also instructs me that I can know some of it by the Holy Spirit, though I will unavoidably be waiting until I have received exaltation through being faithful to the gospel knowledge that has been revealed to me. Yet the hope and confidence that I will someday learn that which I yearn to know is there.
It is sad and difficult for me to accept that it will likely be at least until after my lifetime that I might know and have my Mother in Heaven's presence revealed to me. Because I wonder why not now, why not sooner? I can plead, entreat and beg God to reveal the knowledge that I and others "since the world was" seek. Ahhh, a time to apply Proverbs 3:4, "trust God with all thine heart and lean not to thine own understanding."
Must it stop me however from "ask[ing] of God, that giveth to all men liberally, and upbraideth not; and it shall be given him. But let him [or her] ask in faith, nothing wavering?" (James 1:5) And must it stop the leaders of the LDS church from asking for this knowledge to be revealed in the hopes that we might know sooner?