The point is the She-Hulk is the big guns of the Marvel Universe.
She doesn't have the somewhat mis-shapen body that the Hulk does. Except for the size of her boobs she's pretty much normal shaped. Athletic certainly, but still pretty normal. Although some artists go for the female body-builder look for her, most go for athlete.
But, she's also seven feet tall! So some cgi is going to be involved. But I think it can be more of what was used in CA:TFA to do "Skinny Steve" rather than what they needed for the Hulk.
Actually my top choice for the role would be to go with Denise Masino, but since she's done soft-core porn it'll never happen.