Basically exactly as the title says, currently writing a character that i've always interpreted as acting more child-like compared to her peers but worried that it will come across as annoying. I'm curious about what traits could be perceived as 'cute or funny' vs 'annoying or whiney' so what do y'all think?
I think that you need to start with realizing that the same traits in any person could be seen as either set according to circumstance and the person perceiving those traits. (A lisp might seem cute to a bystander until it becomes very important to them to understand clearly what the person is saying, but that lisp might be annoying to the afflicted at all times.)
Maybe think of why you interpret that character as seeming very child-like? Use that to flesh out what else the character might do. For example, if they have a child-like approach the world, or have simply carried on an armful or two of habits from their childhood.
You need to give them a sad backstory. Read Keeper of the Lost Cities, notice Keefe Sencen. He has had a hard life, and he cracks jokes to get through it. Perhaps do something like that. Give them a crush. One they can tease and tease but would die for. Let them crack goofy jokes but when it matters help comfort.
Hope this wasn't too confusing. If you have read KotLC then Keefe is a pretty great example for everything. Feel free to take my suggestions or just skim them and keep living life, no hard feelings
Childish has many sort of sub-personality traits, its kinda an umbrella trait for a bunch of stuff. Are they childish because of these traits (like naive, hyper, playful) or are they childish because of something they do or like (cartoons, plushies, rhymes or jokes)? If they act child-like in both aspects maybe focus on the 'good' sub traits, like being trusting and thinking the best of people, or being optimistically stubborn (not necessarily a 'child' trait but often seen in this sort of trope).
its all about 'kid logic' for me. the first thing i do when writing a child/ childish character is to think about how they'd react to certain situations. "did you eat the last cookie?" do they lie and play innocent or laugh and run away? what happens when a small inconvenience happens? do they get hopeless and frustrated "everything's ruined", or do they blame someone else, like a friend or sibling? do they accept orders/being told what to do? are they relentless and stubborn with wanting to have their way, or do they give into requests with passive-aggressive "FINE" 's or "UGH! Just stop lecturing me!" just think up a scene/ the situation you need them to be in and imagine how their mood/habits translate into behaviour.
I have a character named Blue, she's a dragon. She's very bubbly and energetic, but not to the point where she's annoying. Some characters get annoyed just because of how hyper she can be, but she's not irritating to the point where she's unbearable to be around.