This has been asked many times. :)
Our family has this tradition where before a celebration (birthday dinner, Christmas dinner), we would all hold hands and sing this silly Irish song (called “Jiggy-jig”). Something that my Dad loved to do, and my 6 year old niece and nephews loved, as well (though, when the nephews got to be teenagers, they cringed for a bit when we sang it :)) Anyhow, it’s just something silly that we did as a family.
My Mom passed away a little over three years old. So, Jmah, is short for “Jiggy-jig, Mah”. Now, when I sing the “jiggy-jig” song, I look up to her.