Good Luck to your kid, she,s right 125,s are where it,s at. Hgs pipes make a special pipe for a KX 144. I have a new Doma pipe for a 03 KX 125 , unless there was frame changes it should fit a 06, I,m no KX expert though, 200 for the pipe. I have 2 cr125,s , one is mod with a 2mm stroker crank and 2mm overbore, with a gp wiseco piston which is quite a bit heavier than a stock piston. I think it makes the bike feel heavier, but the straight line power is impressive.