I need help with a cad drawing for a nesting doll toy.

You need to do is decide what they will be made of, and how they will be made.
Are they plastic, and injection molded? Or, wood and turned on a lathe? How is the artwork being applied?
There are pro and cons to each. The method of manufacturing will dictate how the CAD models are designed.

Just my opinion, but plastic = garbage. Wood = quality (assuming the artwork is painted on).

Here is an example with very similar animals: https://www.amazon.com/Arsdoll-Matryoshka-Handmade-Stacking-Decoration/dp/B07BLYWMLM/ref=sr_1_13?keywords=stacking+dolls&qid=1569190889&sr=8-13

Hy all, Hy Leslie
i´d have take a look on your project, the CAD-DATA generating toolkits you can use still have verry different aproaches, the nesting of the items you presented here are tricky note the following: "keep the focus on/about the stability and the dividing-line (cutting-line) if you want to use rubber-material. The statics of the lower part should be higher tan the upper part for an unproblematic mecanical reconnection, if you want/can made/use a majorate thiknes-design on the surface think on the TEXTURE eg. Fury-texture ... This ist almost important if you want made it thinn or in a soft rubber (less tah 40-50 shore ...)"
Please answere (4U) the following question: how big are the series and how big are the doll sizes ?
This can give you a better aproach on the right manufacturing- and design-recuirements, finaly they determine the key to start on the Answere you search ...
KR / Best wishes Otmar M.