You aren't expected to know the names of tests. What the testor wants to know is what behaviors you're concerned about; not what tests to give.
My grandchildren have been tested for similar issues as well as for a speech delay and sensory issues and received treatment during the past 8 years. My daughter started with the pediatrician. For my grandson who was 2 1/2 she started with the school district at the recommendation of the pediatrician. Federal law requires that they diagnose and treat.
Later she learned about starting with a developmental pediatrician and wished she had involved him from the beginning. At no point was she asked to name tests or even asked what to test for. Knowing that requires the expertise of the person testing. She was asked to describe his behavior and her concerns. The professionals also observed and added their own concerns.
I suggest that it's good to have one person managing testing and treatment. That person then refers to other specialists as needed. A developmental pediatrician is trained to do this. The school district has a special ed office that also does this but they are limited in resources. My grandchildren have received both school help and private help thru their insurance.
After your SWH: You won't know the extent of your daughter's situation in 1 or 2 visits. You may not even know where to start with providing help in that short period of time. We are still learning more about what my grandchildren need many years later.
There will not be an easy one step solves all sort of answer. Development is complex and continues for years and years.
I suggest that you need to know more about this specialist. What is her training and experience? Does she specialize in developmental issues or is she more about diagnosing ADHD issues? You've mentioned a broad spectrum of concerns and I urge you to have a specialist that deals with a broad spectrum of developmental issues.
Yes, you can start with determining or trying to determine if she has ADHD but know that she's too young in many experts opinion to even make that diagnosis. Also know that ADHD type behavior is rarely as simple as a simple diagnosis. Other developmental factors often go along with that issue, especially during the preschool years.
You mentioned that your counselor hasn't heard about your child. How does she know that her collegue is the most appropriate one to do the testing. I would question their ability to diagnose if they are in deed asking you what tests you want run. It sounds like this person administers tests and is not involved in diagnoses and treatment.