I recently had the same problem trying to mark a dark maroon batiq border. I found a marking pen that worked great for me. Chalk was no good, as I hand quilt, and the chalk just doesn't stay with all that bouncing. The pen I bought is a white marker, very fine point, and is removed by ironing, although the quilting stitches covered up that line, so I did not bother ironing it. It is made by Clover, but I see no name on the package except "white marking pen-fine" I think I bought it on connecting threads web site, although I did see one in Joann's the other day. I was really pleased that I could mark the border all in one shot on a flat surface, instead of trying to mark every three inches or so as I went along. I don't know if this will help you finish your beautiful ny beauty, since the fabric you used is satin and maybe cannot be ironed. I think the price was around 6 dollars.
I use that pen all the time, and love it! If the fabric cannot be ironed, the marks can also be removed with water...it doesn't take much. The price at Joann's is usually around $6.00, but that's a great item to use your 40% coupon on! Connecting threads had the pens on sale earlier in the year. The price was even better, so I stocked up a little. I have also seen them in the Newark Dressmaker Supply catalog, and I believe the Clotilde catalog also had them.