Hearth fires change shape/size/colour or become more elaborately designed as a character grows. Might be the combined total of all stats/skills, total LP, etc., that determines the current hearth fire stage.
Low strength character looks weak/lanky, high strength character looks strong/muscular. Not too sure how visual indicators for other stats might look, “brainy” for intelligence or something?
The visual indicators should be subtle rather than glaringly obvious, but I think it would be nice to have visual details on characters or their hearth fires that offer hints relating to their stats for both practical and aesthetic purposes.