Check out the Museum of Fine Arts or Google Art Project collection. Browse with your child. Find one piece of art that your child enjoys. Discuss all the things they see. Using materials at home, recreate the piece or create their own version.
Go on a museum visit virtually all across the world. See this link.
Metkids is full of fun art related activities to try at home.
The Melrose Art website includes many activities created by our own Visual Arts teachers.
Follow Your Art Community Studios is posting *daily* art challenges that you can do at home with minimal supplies. Find them on Facebook or Instagram.
The children's author, Krosoczka, will be hosting webcasts every weekday at 2PM EST so much imagination!
Check out these live lessons from children's illustrator, Mark Kistler, everyday at noon. It appears these are being recording. Here is a link to the first video.
Check out these drawing tutorials too.