My daughter has Asperger's and had school refusal. It was awful so I understand how stressful this is.

Im sure youve told your kids this, but its important for them to know that going to school is not negotiable. After my daughter stayed home a couple of times, I got the school involved. She was very explosive but I did my best stayed calm and explained that it is against the law and considered child neglect to skip school. Then I told her I was calling the school to speak to her vice principal, which I did. She told me she would meet me at the door, just to try to get my daughter there.

I think hearing the principals voice on my phone worked, because she gave in and went. The
principal, vice principal and adjust,met counselor all came out to meet me. They almost had to carry her out of the car (I gave them permission)...the principal even got in the car with her.
Eventually, after about 30 minutes, she got out and ran, but the school staff told me to leave. They said shes on school property now and its their responsibility to handle it. I did feel so guilty but I could see out my mirror that they were firmly but still gently handling her and she began to walk in voluntarily. That was the 4th and most dramatic incident we had and was also the last. I did find that when I called the school in the midst of the turmoil at home, they
were very receptive to helping me in most anyway they could. I think if they see a parent being active in the moment, rather than reactive after the fact (which is the natural response), school staff responds much more positively to the situation. I know another family whose daughter had exactly the same behavior, but was 13 and in middle school. She missed so much school and the parents had little to no support. They had strained relations with school staff and our experiences were like night and day. We still had issues, but more tardiness (by 30-40 minutes) than refusal.

Has the school counselor talked to your kids about why they don't want to go to school and made sure there wasn't something there that was stressful for them? I have the DSM 5 and don't remember "school refusal" as a diagnosis in itself. It's probably a symptom of other diagnoses like ODD, but I don't see how that matters unless her T wants to get something written into an IEP about it. They need behavior plans implemented in the school. Unless your daughters T communicates with school staff a lot and, and it doesn't sound like she does, a home behavior plan won't do you much good. I've been there- you need help. Will your daughters T go to meetibgs with you? Many will and then she can explain further what issues your daughter/ children have and try to come up with a plan. If school admin still doesn't cooperate then Id hire an advocate or special education lawyer.