Maybe it's not the bells and whistles, as most quilters really only need straight stitch and a 1/4" foot as someone else mentioned.
Maybe it is the fact that her machine doesn't work well and is frustrating to use. If the stitches don't look good, then, you have problems with the tension, then sewing can be more frustrating than enjoyable.
So, my advice..find out why. If she just "wants" bells and whistles, then tough (as many people want that--many experienced seamstresses.) If, however, she just wants a machine that sews beautifully without frustration, I think we are all here ready to help.