Having worked with lots of kids in the school system, I can say sometimes there isn't a diagnosis. It just seems like there should be, but there isn't.
Unfortunatly, that means you're charting unknown terratory. There are no people that went before you and you don't know what the future holds.
I'm sorry that no-one who's seen her knows a diagnosis.
Beyond a diagnosis, is she getting treatments for your individual concerns? Speech and gross motor therapy will help no matter what the future brings.
Have you explored Williams Syndrome? The literature talks about how friendly the kids can be.
http://www.csmc.edu/csri/korenberg/f...sdssshort.html
Characteristic facial features are described as "elfin." In the majority, valvular stenosis, poor growth, hypotonia, late-onset contractures, dental anomalies, infantile colic, oral-motor discoordination, and hyperacusis (ie, hypersensitivity to sound) are reported. Infantile hypercalcemia may be transient and is often subclinical.
Mild to moderate MR, relative preservation of language, and associated weakness in visual-spatial development are typical.
Elastin is the candidate gene presumed responsible for some of Williams syndrome features, including supravalvular aortic stenosis."