If Mya started panting after playing suddenly, that may be a sign that something might be wrong. If is has been hotter than normal, and suddenly, that might explain the panting. It is difficult to say without the ultrasound whether she has a problem or not, unfortunately. She seems quite healthy otherwise, but if the panting is a dramatic change, having the ultrasound will let you know what is going on with her.
The Russian blue is a sweet-tempered, loyal cat who will follow her owner everywhere, so don't be surprised if she greets you at the front door! While she has a tendency to attach to one pet parent in particular, she demonstrates affection with her whole family and demands it in return. It's said that Russian blues train their owners rather than the owners training them, a legend that's been proven true time and again.