Sounds like you are already off and running, but there are usually 3 concerns with silk, laundering, fraying. and pin holes. Since it looks like it launders ok, the next issue would be fraying. i would probably stablize the silk with a light weight iron on knit interfacing. Using a knit, like tricot, will not change the hand and will keep it from fraying. If you've already stitched it into the quilt, re stitch using a small stitch length. The last thing you have to be careful of is that pin marks will often remain, which means if you quilt it and then decide to remove the quilting stitches and re do it, the original holes may remain.
Good luck and can't wait to see the pictures!