I can certainly reduce the minimum height of custom girls to 4' 0", I'll include that in the next update.
I'm open to new in-between weight stages but I want to make sure that each stage is a clear shift in fatness. My logic behind the current stages is that the girl starts skinny, then at 'Slightly Soft' you see the first signs of fat appearing on her figure. At 'Chubby', she's now overweight, but not yet fat, followed by her becoming officially 'Fat'. There are then the three following stages as she gets increasingly large and mobility begins to decline, followed by hitting immobility and then a final stage where she's so large that she needs full time care.
I'll have a think about what new stages could be fitted in there using this philosophy, let me know if you have any ideas.
I'm planning on adding the beach as a new day trip option & canals might make an appearance in the game too, thank you for all your suggestions. :)