Oh boy, it sounds like you have a little whirlwind on your hands. I feel for you because a toddler is in many ways more difficult to work with then say a 6 year old. If she was older you could just let her run around outside and burn off that energy, but thats a bit harder at her age.
However, physical activity for little whirlwinds is very important. Don't make her stop moving! She needs to move and the more she moves, the better she will be later on. Anything you can do to get her active after school will help!
And yes, there is a decent chance that she might have something like ADHD. I am not sure that the people who you have booked appointments with can diagnose that, but hopefully they can refer you to someone who can.
So what can you do. As you found out with the biting, timeouts if followed through can help. But, she is doesn't sound like the typical gal that responds immediately to timeouts. In fact, research shows that it takes about 3 weeks of very consistent behavioral modification (of which timeouts are) to get a change. There are two really good books for parents that might help you. They are..."SOS Help for Parents," by Lynn Clark and "One, Two, Three, Magic" by Dr. Phelan. The SOS book focuses on really effective ways to use timeouts and might be your first choice.
This link might also be helpful (as well as others by the same group) https://childmind.org/article/how-discipline-toddlers/
Finally, there are there are books aimed at the 4 to 7 year old crowd that are meant to be read aloud (many times) to them and then practiced. A good example is "Cool down and work through Anger" Which can be found here...https://www.amazon.com/Cool-Through-Anger-Learning-Along%C2%AE/dp/1575423464/ref=pd_sim_14_1?_encoding=UTF8&pd_rd_i=1575423464&pd_rd_r=73N8M9HNCA27XTW48JYV&pd_rd_w=oKQ3h&pd_rd_wg=QIDI6&psc=1&refRID=73N8M9HNCA27XTW48JYV
And on this link, you will find other books aimed at this age group. The books are really good and can make a difference.
Finally, here is a link to a post that Specialmom and I did back in 2013 that has a lot of info that might help. We come in at the end of the discussion, so scroll down to the bottom part. https://
www.medhelp.org/posts/Child-Behavior/my-4-year-old-is-out-of-control-what-do-i-do/show/2023048
I hope this helps. Keep in touch!!