wildyard

I am making a "big girl" quilt for my 13 yr old granddaughter. She is very active in dance, taking 4 classes and also being a teacher's assistant in 2 others to help pay for her classes.
She is also athletic and has fallen in love with volleyball.

I took photos of her feet in her dance shoes, then cut her feet away and just used the shoes to make a block for each type of dance, jazz, ballet, tap and hip hop. I also created a volleyball block for the quilt.
I am very pleased with all of them except the ballet slippers not showing up so well on their fabric.

I will either use black thread to outline them, which concerns me because my stitching skills are not that good yet. Or change the background fabric.

Would any of you suggest using fray check on the edges even with the iron on backing I used? If I did that, I would feel safe to do a straight line stitch around the shoes and could do a better job of that then I could with the zigzag. I used a shiny fabric for the pink and beige shoes and it is ravelly.