I don't think it was too difficult. However the cotton drapery fabric I am quilting now IS difficult. I have actually broken 3 needles quilting this one.
I think it depends on the tightness of the weave and the thickness of the individual threads of the fabric. Silk can be very light and pliable. Most of the samples I have are from India and are light-weight. Also, they are solids or stripes without any embroidery or over-weaves.
I'll let you know!