I would make a very serviceable but nice quilt for her following the good advice given here, but keep the scraps. Then knowing that 1.) it may be stolen or ruined and 2.) MIL is needy (=lonely) I would ask her if she would like to help you make a quilt for her from the scraps. This way you would be keeping her company and would have something that would remind her of her momma once she is gone.
Perhaps this way MIL will get a new hobby to fill her time; you both will have something you can talk about on the phone and decrease the need for DH to drive back and forth all the time.