Seems she's not on the tiny side at all. More when compared to the original design.
I don't mind st all the bust size increase on the new design,but it may seem a little bit of anti-intuitive,given that her main thing is been a speed runner.And speaking of which it seems like her "speed power" is more like kind of a "ninja run" than a "Flash's super speed" deal and it is something they use in screen only when needed and not something they hit you in the head with every episode,as if they need to constantly remind you "she's Cheetara,she's based on a cheetah,she runs very fast" like they loved to do in the old cartoon.
Also one thing I notice is that some character design bear a certain resemblance to the ones used in Avatar:The Last Airbender.
Now,I know Ethan Spaulding,who was heavily involved and directed several episodes of Last Airbender is the producer of the new Thundercats.But I don't recall him been involved in character design.