I think you are doing the right thing in upping antibiotics. I would increase until you see resolution of symptoms and maybe a bit after. Many on this forum say 30 days or more.
Now this is in my own opinion but following this treatment. What are you doing to keep her healthy?
I think once symptoms resolve you should be working on inflammation, she still has some or no symptoms would appear with illness. Then you need to work on immunity. Vitamins, supplements, probiotics ect... Keeping her as healthy as possible is so important.
You may be doing things to support this but may not... We use a super vitamin called IntraMax to help immunity and things. And we have been using essential oils (with miraculous effects) for inflammation.
DD got strep 10 day bf school began. She had a mild increase in tics, which were pretty non existent and our last symptom) Last year she was an emotional mess with strep, crying, 12 tics, separation anxiety, and all kinds of othe symptoms.
PM if you want. Good luck!