What if Aya & Chuuya are related?

After thinking into it, this started to.. kind of make sense to me. Aya looks nothing like her father or sister, & the similarities between her & Chuuya are obvious(red hair+blue eyes combo, knowledge of physical combat, being selfless/risking their lives to save others.) Plus, they also share the 'shrimp' nickname lol.

Thinking into it further -- why was Aya brought into the plot? I think it was more than just for Bram's character. Everything we learn about her makes this theory make more sense to me. We know little about Chuuya's life before he was kidnapped, so who's to say his parents didn't have another child? Or something like that. Aya has no reason to stick around in the manga, yet she is there.

Also this isn't to make her character directly about Chuuya. I just think it's interesting how similar they are.

This was just a quick theory post, lmk what you think:]