I'm not sure how the Grace frame is set up. On my frame I have a roller bar on the back called the TAKE UP BAR. This is the bar the quilt is rolled onto when you have finished quilting an area and have to advance to the next area. You should have a leader on this bar that only the backing fabric is attached.
On the front I have two bars nearly on top of each other. The upper bar is for rolling up the quilt top. You attach a leader to this bar and attach the bottom edge of the quilt to this bar. The lower bar is for rolling up the backing of the quilt. You attach a leader to this bar and attach the bottom edge of your quilt backing to this bar.
For attaching the quilt and backing to the leaders I use CORSAGE PINS. You can also use T-Pins but the CORSAGE PINS are cheaper and it is easier to grab the pins. You should be able to find CORSAGE PINS at Wal-Mart in the floral department. There is about 144 to a box and it costs around $5.
You can either take one "big bite" of fabric per pin or you can "pin stitch" with each pin (going up and down several times looking like stitches on the pin shaft) These are placed end to end.
You always go thru the leader first. This does create a little "fold over" but gives the cloth extra strength as it is streatched between all the rollers. You might look on U-TUBE to see if you can find a video for LOADING A QUILT onto a frame.
I hope this helps, if I've not been clear please let me know and I'll try to explain a bit better.