Happened to me once After reading a book that had nothing to do with drawing next day it was improving fast on my realistic art skill c': when i saw what i had drawn a week earlier compared to it i was like woah.......i drew that a week ago.....oh well :'''''''''')
Everyone has their improvement spurts, just like some people dont have a set style or anything, is perfectly normal. Tracing and stealing can easily be distinguished, I don't know why everyone is so suspicious
I mean a month of improvement is good, even a week is kinda okay. If its like I draw something decent today and next day as you said paint the monalisa than yeah something is up... unless they were lazy and actually had the talent but didnt put the effort for all their work and just decided to do so one day.
1. i've had things i like to call "improvement spurts". this year i had a lot of improvement on my humans in 4 months,and normally not even in 3 years would i manage to achieve that 2. depends how much. a few weeks is ok,unless one day they draw something that has very shaky lines,bad colouring,lots of anatomy mistakes and the next morning they'd be painting the monalisa then yeah it's suspicious and questionable