Dora first documented sketch on 11 August 2013.
A reflection of what is cited from Babycenter UK:
12 to 18 months
Over the last several months of his first year, your child's fine motor skills improved steadily. Now he's physically ready to grab hold of a crayon and start experimenting. At 12 or 13 months, some toddlers are already able to scribble vigorously, while others start tentatively (they'll drag a crayon around on paper, scrawling inadvertently). If yours takes longer, that's fine, too. Children develop at different rates, some faster than others. By around 16 months, your little one will probably be a scribbling pro, creating a gallery's worth of drawings for the refrigerator.