Some people have problems using spray basting on polyester batts, but I think it depends on the brand of basting spray. People who use 505 basting spray say that it works fine on polyester batts.

how was the quilt basted, pin, spray it might be it wasn't basted enough and the middle is slippery leading to more shifting the the middle. Hope i am making sense.

Pin baste, thread baste or spray baste to prevent shifting...
I use LOTS Of spray baste for center ( spay back to batting and batting to top.. ) and pin baste the edges to keep it from shifting..

I would also make sure to lessen the pressure on the walking foot--not sure how to say what I mean--with my walking foot, I turn down the pressure as far as I can--this helps with thicker batting.

I do the same, I always sew the layers together after I FMG, I then sew the binding on one side, Iron it flip the binding to the other side, glue with washable glue and then iron it down. Then I sew the binding to the front side with the sewing machine.

Me too, except I put mine through the serger. People have told me this won't work because my binding will not be full. I have not had any issues with baggy binding.

Also, do you have a walking foot? Good to use for applying binding, whether you finish the edges some how or not.

I don't use poly for batting anymore but when I did I would use an overcast stitch around the edge to hold everything together. It made a big difference in how it turned out.

How do I lessen the pressure on the walking foot? I know older machines have a knob on the top that will do that, but she is using a brand new machine and I am not sure how to make that adjustment on it, if we even can.

Thanks,
Jp

I don't know what type machine you have, but since it is new, there should be a manual.

It is a Brother sc9500. It does have a manual, so I will check it out.

Thanks,
Jp