Challenging Roto (I think)

Hey everyone!
I have tried on the attached video to roto the woman and i found it extremely hard.

So, i remember that whenever you are struggling with roto, you need to divide it into a small portions.
So i started by just tracking her lower leg… and the plan was to use this layer track, as a track to a precise Roto mask.

However, no matter what i did no matter how i followed the rules i needed to add keyframes time and time again to set the mask to its path.

My only question is, is that notmal in such case to have so many keyframes?

Kindof, cloth is tricky. You could try PowerMesh on this and see if it helps. But cloth is really liquid, so yes, you can definitely have that amount of keyframes or more with it.

Yaaa ba daba duuuuu!!! Thanks Maaryy!