You may not like my answer, but if it makes any difference, you are far from alone on this journey. Many families and adolescent or near-adolescent children with diabetes fight these very same battles. This is now (and has been) a power struggle between authority figures (parents, school, doctor) and your daughter. For now, she is, and likely will continue, winning. How completely obedient and subservient were you to your parents when you were 11? But, now you have years of maturity and wisdom and foresight to see that your daughter is slowing doing herself harm.
She needs psychiatric counseling NOW; the school counselor will be out of their league. She needs discussion about her defiance of her medical plan – subtle or not – and some guidance as to work out any passive-aggressive tendencies. AND, the parents need counseling too! Thus, family counseling, together and separately, are required, I think. To add an even larger challenge, do you have such a counselor in your community — let alone one who has experience working with children with complex and chronic medical diseases?
Some other medical adjustments could be attempted in the insulin plan, but you did not share her diabetes regimen. Share your concerns and frustrations with her pediatric endocrinologist. If you are not followed by one, it might be helpful to get a second opinion, but share on the front end when you make the appointment, that you have these issues to address. The pediatric endocrinologist or your regular diabetes doctor may be able to make arrangements with a psychologist or psychiatrist and/or social worker to work with that day.
DS