Ccreate continues set of generated images - same style and characters

i want to create an “avatar” from a picture (of my son for example), then start telling a story, each tome different scene but same characters and keep same style of illustrations

for this i would need a good “avatar” model creator, and image generator that can be consistent enough

can anyone help with best models / sites they know of?
Tried dalle - wasn’t so successful on keeping the style consistent