I always figuere 'yo' to mean 'years old'... when not obviously refereing to a yarn over.
And I also guessed that DD/DS/DH/et cetera mean Dear Daughter, Son Husband Et certera. Could be wrong about that though.
I'm a teen knitter too... although not for much longer, since I'm 18 already. Sadly, college gets way too much in the way of my knitting time, so I haven't done too much guilt-free knitting this last month.
I try and reason that I NEED to knit on my Fetchings, because they really ARE for school... since I'm into astronomy, so I'm out at all hours of the night with my telescope, freezing to death, and my warmest jackect is too short in the arms. Hhaha. So far it isn't convinving anyone.
If I just didn't have to sleep so much... Think of how many extra hours that would give me for knitting! Hhahah.