VaM 1.x I want to create Elastigirl in VaM

The only option I see would be to apply specifically made morphs for the purpose.

Morphs are one thing, but this won't help on a thing like her as you won't be able to control the limbs like in the movie. Having elastic limbs would require more control points (so a specific skeleton).
You could fake it with a physics based CUA, but that would need a lot of work to look good.