"Smart, but Scattered" and "Late, Lost, and Unprepared" are two books that have a lot of great ideas on how to teach executive functioning, including impulse control, organization, remembering routine tasks, etc.
The techniques used in Occupational Therapy to improve sensory integration can probably help make any sensory over-excitabilities more tolerable for your DD. Try googling "Sensory integration" and "sensory diets" for things you can do at home that might help make your DD more comfortable in her own skin.
None of this should take precedence over improving the academic fit for your DD right now, as gifted children in an under-stimulating environment have extraordinary demands placed on their attention and executive functioning, being asked to attend to information that they may have known for years while having to continually resist the impulse to do something interesting and intellectually appropriate, like start a conversation with a neighbor about a topic of interest. Getting the academic fit right makes it a lot easier to determine what behavior was due to improper academic placement, and what, if any, issues still need 'tweaking'.
