What Causes Twitches In Shoulders?

my 8 yr old daughter has recently started with a twitch in her shoulders, she was diagnosed a few days ago with the stomach flu and a UTI, she was not dehydrated, but i have since noticed the twitching, iits been about 4 days now that i have noticed her doing this. i watch her when she sleeps and she still twitches, but not as much. i have asked her if she is in pain anywhere else besides her tummy and she said no. Should i be concerned?