A finely woven cloth will be just like paper. My sis in law home schools, do you think this would be an appropriate project for an 9 yr. Yes, there are many simple forms of origami published in books everywhere. Select a form simple for the young ones. Glad you asked about silk.
Silk is special in many ways.
I would use a dilute solution with silk. Also if you are using a finely woven silk, be careful as it will tear just like paper. It is unlike any other fabric. But like most textiles with a sheen, that sheen will be lost when the solution is applied. There are many other facets to silk besides its sheen, to take advantage of.