Trying to cater to all types of audiences, I thought about including something different in mom's help 2, older sister Jenny will move a little towards fitness. What do you think?
Her body won't simply change, it will happen gradually throughout the story.
leave your opinon about it.
My 2 cents: I really like fit women (and I also like variety ;-)), but in these images her arms look too skinny to me even in her "less fit" version, perspective could play a role here, but regardless in the "fit" one, the difference with the rest of her body seems even worse.
also, often in 3d renders of more muscular women, the pectoral muscles and shoulder muscle don't seem properly attached (normally, these pectoral muscles "attach" over the biceps (You could say that's why we have armpits) but in these weird renders, the biceps seem to start -or attach- in the middle of the humerus (the upper arm bones) rather than at the "shoulder" joint. The lats also are weirdly attached in the back, they don't "flare up" to the arms properly.
As a result the arms look weird (here it's not the case in the front (I think I spot the lats issue). but maybe it's only because she has no muscle on her arms, maybe that's even why you designed her this way).
Without this issue with her skinny arms, I would prefer the fit version. Everything else looks great! But that could be contrary to your core audience. Anyway, since it's a gradual evolution, you can adjust the "definition" of her muscles at the end, where she would end up in-between the 2 versions.
Edit: also, fetishes aside, (properly hydrated) fit people don't look as "cut" as the "fitness 1" image, unless they are flexing or engaging in intense physical activity. So you could use "1" in these situations and a variant of 2, but slightly curvier in the areas with more muscle mass (legs, back, belly, upper arms...) for her "rest" look.
