After long consideration, I concluded that 5 pose would be enough for front standing illustration, given this combined with facial expression can deliver most of the possible emotions of the character.
Incidentally, this is the story from a developer's perspective, the more pose the character have, the more drawings for her top clothes, and this means longer time of development, which means the release of the game will take longer...
However, we also prepared additional illustrations for describing pregnancy status. We're planning to have 4 steps of pregnant body as shown in the picture.
Plus, the basic underwears and clothes are prepared. Each pieces could be independantly put on and off, and 11 body accessories are prepared now.
So.. yeah I think this would be enough for now, I guess!