Then, Ayame would follow up with her own roundhouse kick, aimed at Blair's body! This was a textbook counter. While throwing her kick, Ayame's left hand would raise up to protect her head and her right arm would swing downwards to create momentum. Ayame's kick would come out quickly, giving Blair little time to react.
Meta Information
One option would be to raise her right leg/knee to do a high check and block Ayame's kick.
Another option would be to use the momentum of the whiffed roundhouse kick to launch another spinning attack (i.e. spinning backfist, spinning back elbow, spinning back kick, wheel kick, etc). However, Ayame has her left hand up so she would be somewhat protected against a spinning attack, since a spinning attack to the head at this point would be coming towards the left side of Ayame's head (an attack to the right side of the head would be going against the momentum of the kick). Even if Ayame blocks the attack to the head, however, it still would not be pleasant to receive such an attack. Alternatively, Blair could go to the body with a spinning kick, either targeting Ayame's side or front. Ayame's elbow would provide some protection against a spinning kick to the side of her body, but her front would be relatively unprotected at this point (so a spinning back kick to the body could work). Moreover, a spinning backfist or a spinning back elbow to the body would probably be very unlikely as I believe that those strikes are usually thrown to the head (I could be wrong about that though).
A third option would be to throw a side kick with her right leg, although that would probably be less likely since Blair's base is in Muay Thai and Muay Thai does not typically utilize side kicks (side kicks are more heavily utilized in Karate and Taekwondo). If Blair threw this, it would catch Ayame off-guard.
A fourth option could be to throw a backfist with her right hand to try and hit Ayame either straight on or on the right side of the head (such a move would not be likely as such a move would strike be as more "Karate" than "Muay Thai"). It would be quite surprising if Blair threw this (probably even more so than if she threw a side kick) and would potentially capitalize on the fact that Ayame swung her right hand downwards during her kick. Again, I emphasize that this would be VERY unexpected and also VERY unlikely for Blair to do.