I haven't made a full quilt yet, still collecting kids shirts here. I am so sorry for your loss, I cannot imagine losing any of my kids or grands. Sending cyberhugs ~ and hopes your heart heals soon. Making the quilt may be very therapeutic, it was for me after losing my mom and grandma.
Test a few different stabilizers, there are many that work, but you may find one that you prefer. You can buy as little as an 1/8 yard at JoAnn's to test them out (like on a sleeve of the shirts)