Yes, I would definitely fight to keep the eligibility through the school. In my experience having it will open the gate for services depending in the state you live in. Check your state's autism regulation and services your child is entitled to. For example, here in Texas we have autism supplement which consists of 11 items school district have to consider ithe IEP meetings. These iclude behavior services, in home, family support, behavior support, social skills, summer school etc. You are correct in saying behavior might interfere with academic progress.... You can ask to get social skills and behavioral goals to be added in her IEP once she qualifies for special ed services. Seems like she is getting ABA which is great. You need to educate yourself because school will not give you the info :) and doctors/ health care providers often have no idea.
Wright's Law is a great website to get info on advocating for your child in the educational process. Best wishes.

The problem now is that my daughter is educationally ok, but is behaviorally behind like with social skills and staying on topic. The school is giving us ABA counseling with her teacher. Our concern is that the behavior will impact the education at some point. Right now she is in K and may fall back in the pack or behind.

Although medical and educational evaluation might use similar evaluation tools the purposes for the diagnosis is different.My son has Pddnos medically and Autism educationally. The medical route will
just tell if your child meets criteria for ASD while the educational should use a multidisciplinary team if professionals. They will see if criteria is met PLUS if he has the need for specialized instruction IEP to be successful at school. If he does he has educational eligibility
Of autism thus he can get special education and autism services. If you do not agree with the public schools evaluation. You are entitled to one outside/ private educational evaluation that the public school
Will pay for. Best wishes!

I would take her to a neuropsychologist for testing. That would give a fuller picture of her strengths and weaknesses in addition to clarification on the appropriateness of the PDD label. A NP tests things like IQ, visual and auditory processing, attention, working memory, fine motor control (to diagnose dysgraphia), and so on. If you get a referral from the developmental pediatrician or a pediatric neurologist then your insurance should pick up at least some of the tab for the NP eval.

Sometimes it's unclear at first to give the autism diagnosis