no matter what machine you use it's all about the tension on the fabric (vs tension setting on the machine). Sounds like your Mom's table set up provides better control of the body of the fabric which reduces the tension. Table extensions are great, but there are tricks you can use if you don't have one - hold the unsewn part of the fabric on your lap or throw it over your shoulder so it doesn't drag so much (letting it hang to the floor either in front of or behind the needle increases the tension/pull. Don't force the fabric either by pulling or pushing - let the machine feed dogs pull the fabric through with you only guiding it. Try "puddling" the fabric - keep extra fabric piled/puddled up around the machine - again, to reduce the drag/tension when fabric moves through the needle area. If I'm sewing a long seam I often fan-fold the material then drape it over my shoulder so the fabric feeds off my shoulder and not my lap or the floor. Takes some time to fold/adjust, but reduces work and frustration later. Keep readjusting your material so that there is no drag around the needle. It will take a little practice but you can do it.