Okay, I think the age gap is just two years (if she's 8 and he will be an adult in 8 years, so he's ten).  Second, they are not related.  But of course, point 3 is absolutely valid.

Ml ??<img src="https://rx.rzyn.net/stickers/pepe/31.webp" class="sticker" alt="pepe sticker" loading="lazy" /> i don't know i somehow feel like he is not the ml<img src="https://rx.rzyn.net/stickers/pepe/2.webp" class="sticker" alt="pepe sticker" loading="lazy" />just brother figure?...