As a neuropsychology doctoral student, I have done research on children
with Spina Bifida and most of these kids had some level of an
Arnold-Chiari malformation. However, having one does not necessarily mean
surgery, nor does it have to indicate something seriously wrong. There is
a small percentage of people that have A-C that are only discovered
through incidentally from MRI of the head and neck for some other reason.
The question is, what KIND of A-C does she have? If it is 1 or 2, then
little if anything typically is or needs to be done. Levels 3 and 4 are
another matter and if she had an A-C of this level, she would likely have
presented to the neurologist much sooner as these are more serious.