Sounds like she has a buildup of ammonia possibly. That was happening to me for a while. Then i started to take something that will reduce ammonia in my body and the twitches go away. I take ammino acids to help with that including L-arginine and L-ornithine. Since she is young you may want to take her to a toxicologist to do some blood work ..they will tell you what chemicals are in her system and may be causing the twitching.