>>3424017Canonically, she has absolutely no combat ability whatsoever.
However, she's masterful with what can best be described as "memory magic" - rewriting peoples' memories and restoring them to exactly as they were later, accessing memories of other hearts that are hiding within people, and even using peoples' memories of each other to determine the identity of, locate, contact, and communicate with a literal suit of armor powered by an autistic level of rage. She's also survived ceasing to exist, so that should probably count for something.
>>3424058I wouldn't be surprised if, by this point, Naminé is afraid of scientists, between Ansem the Wise acting as an overprotective father during her stay in Twilight Town and Vexen and Zexion being creeps in Castle Oblivion. I wouldn't tease her for it - just as she likely wouldn't tease me for my fear of poor structural integrity.
She has no canonically defined height, but most estimates put her at around 5', meaning she's about a foot shorter than me. And that's adorable. I'd probably tease her about her height, yeah.
While she probably wouldn't keep a traditional diary, she has a tendency to draw events important to her, and display them wherever she's living at the moment.
>>3424089I think, at that point, she'd be relieved that she actually corporeally exists for more than a year at a time. She doesn't have any particular ambitions of her own - everything she's done in canon has been either to help someone close to her or spite someone who's wronged her, so a simple life might be nice for her. In addition, due to the very strange circumstances of her being (especially as of KH3), gaining weight might not actually be possible for her.
>>3424119The only artwork I can find of Naminé waking up is artwork shipping her with Roxas. That being said, I'm not particularly good at searching for images.