I really don't mean to scare you, but my biggest worry would be when she is in high school or college and will still be the youngest kid in the class. When is her birthday? In California, they finally changed the law that said you had to turn 6 by Dec, and returned it to Sept.
The teachers are calling home to complain because it is their responsibility to do so. I do wonder what they said in first grade? Kids don't change overnight. It may be that her immaturity shows up more now in comparison to the other kids. Or her teacher expects a lot more than the first grade teacher did?
ADHD does not just start up at age 6. Read some of the other posts on this forum. Most parents notice it long before than. This does sound like its more age related (if nothing has happened till now). If she does have good intelligence, she will figure out what she has to do to cope with the school's expectations. You can help her at home by trying to make her aware of when she is getting carried away emotionally.
Anyway, I hope this helps. But I really need more information about what her past school experiences have like. And I do worry about her age if she is a Dec. birthday. A Sept. birthday is not quite as bad.
I understand when you said u are afraid by all those terms. My boy has now 9 years, he is born in August and he had no problems during the first 5 years at school and suddenly he became too slow for his class; slow in written. I read many articles on the web and was scared like you when they mention that "slow" may be equal to "ADD". In my heart I cannot imagine him taking medication. But I didnt want also to underestimate the "problem". I am not an expert, I am just a mother, and I am facing a problem with my boy too, but we started acting in close cooperation with the teacher who is a great women. However I know that u will not feel better until u talk abt ur child behavior to an expert, a "psychoterapeute" or else- (this is in french, sorry ) to find out if there is a real problem. U said teachers are complaining... why? a good teacher should be able to deal with all situations, and when necessary to help, support and coordinate with experts in the school and with the parents to find a solution to the problem, if there is a real problem. I would like to know what a "30 years teacher" think about this.
I knew recently that there is a kind of regulation or law in US concerning the support that the school should provide to children diagnosed with ADD or ADHD or other....
So please dont panic, there is always a way out. Be confident. Reading other posts in this forum may help u to take the right decision, as it has been for me. Good luck