the quilt should have been listed on her Personal Belongings Sheet in her file. Since the quilt is missing then I would file a Police Report... there are Light fingered employees that are working there that should be punished and fired..
It is a CRIME to steal and I would make it known that you are contacting the police or Sheriff...The person who did the stealing if they are CNA or STNA and are caught they will Loose their License...
If your Granny is declining in Health then make another easy quilt and Tie it... Take Several photos of it with her and put a photo in her file... and you keep the other photos... or if she climbs Heaven's steps before you get it done then make Lap robes for others in the nursing home... Make sure you note the Date you gave her the Quilt on the picture and have the Social Worker or DON or Administrator stand and hold the quilt with Granny and take the photo...
Its a SHAME that who ever took it was that desperate to Steal a Treasured item and may it never keep them warm...