Namaste my Kali Mata. There is no one way to answer this question. There is a moment in chelas life that she or he realizes that Guru is all that there is. In that moment, in the fullness of that moment, the grace comes pouring down.
There is also the Gurus wishes or desire to grant you her grace and this happens at any time and any place or any life time.
You must all know that every one of you have the grace to be at the Guru’s feet. I love you. Love Ma Jai Kali Ma Ki Jai.
Namaste Ma, How does one win the Guru’s grace?
Thank You Ma, Love, Kali Mata