do yall think that Myne is a child or an adult?

I'm currently in the middle of season 3 of the anime, and so far Myne has had interactions with 2 people I could sense as flirtatious: Lutz and Sylvester.

I don't know if any romance will actually be developed, but it rubs me the wrong way with either men. Myne clearly has all the adulthood memories from her past life, but she doesn't in any way behave as an adult, she's like a child was just implanted with those memories without the actual development, after all, her brain is still one of an 8? 9? year old (which I guess is what happened lol).

I've seen many isekai (like youjo senki, for example) where the mc reincarnates as a child but keep both memories and demeanor. This doesn't seem to be the case here, since from the very beginning she acts very differently from what we see later in her memories, specially towards her family. Some characters point out sparsely how she doesn't act like a kid at times, but she doesn't stand out from the other children from their interactions, and when we compare her to older kids like Wilma, it's obvious just how childlike she is. I see way more similarities between her and Frida.

She has very poor control over her emotions, is way too atached to her family (people she's known for what? 3 years?), she has also the awareness of a kid about things like physical contact, a grown woman wouldn't be climbing on top of people's laps out of nowhere searching for comfort. She feels way more like a kid. But she also has the memories and a certain connection to who she was before, which makes me feel weird when she blushes because of something Lutz said or did.

Idk I guess I'm just a little torn and wanted to know others' opinions on this, I'd also appreciate if someone could tell me if she ends up in a traditional romantic relationship with anyone at some point.