What might you think? (Mello x Reader)

"If you had just witnessed the death of a loved one, what might you think?"
~
Unbeknownst to the Orphans of the Wammy's institution, the great detective L had a younger sibling. A little sister, in fact. The little lady was autistic to the extent that she was unable to speak to anyone but Watari or L without having a mental breakdown, though with her neurodiversity came great intelligence. She had remained holed up in a special room that many of the other orphans rumored as haunted, until one day, in a fit of boredom, she wondered out and discovered that the orphanage isn't such a scary place after all...and that the likes of a blonde chocolate eating boy sharpens her tongue and brings about a witty personality that she never knew existed until now.