Honestly how did you even bring that up at Thanksgiving? My cousin tried to say it was alien plant diagrams last year and my aunt just kept passing the mashed potatoes in silence. Next time maybe say it looks like a messed up herbal guide or a fake star chart, stuff that sounds smart but won't start a war. Tbh it's safer to just agree the bikini babes in the drawings are weird and change the subject.
But wouldn't time travel be a bit too easy of an answer? I get where @matthew_stone is coming from, that's a fun guess. It just seems like a jump to go right to time travel scribbles. That kind of thing would probably take way more planning and effort, you know? To me it looks way more like a regular kid just got a hold of a pen and went to town. The mess is too random, not like a message from the future.