Does your DGD ever see you or other adults doing any colouring or crafts ? I would buy myself a couple of colouring books and a packet of felt pens ,turn the TV off and just sit quietly at a table and do some myself. When DGD asks what you are doing , you could say " something that makes me happy/relaxed /calm/that I enjoy ". You could sit her on your lap, show her what you're doing and how good it makes you feel, and my guess is that she will want to join in at some point. Get her to help you with yours.
It could be that she is unsure what to do, how to hold a pencil, etc. Have some blank paper (preferably a A4 blank paged notebook that you can write her name on) and age appropriate colouring books handy,not on display,
"Perhaps you'd like to join me ?"
(Do not worry about how she holds pencil that first few times, that can come later )
Might take a few attempts, but my guess is that once she sees that it is a fun/relaxing pastime she will want to give it a go.
Just a suggestion.