What do you do with them?
Depending on the age... you may want to look into lessons. (If younger, lessons may not be the best idea). With art.. it's a balance when younger with letting them explore and be creative, versus learning. One of the worst scenarios is putting them in lessons where it is simply follow the teacher... like many art projects in school. One wants an art instructor that may introduce them to different techniques and art media, but where the project is still theirs in terms of creativity.

Having access to a variety of art supplies is also very helpful.
Any art museums nearby? Your dc may be interested in attending.

The other difficult aspect in regards to a child that has artistic talent... the age of 8-10, is often a big turning point where kids lose their enthusiam for art... they see they are not 'good'. It can be hard for them to navigate that phase.
Tammy