10 week old cant hold dummy?

I have a 10 week old daughter and i give her a dummy which she does like and will take but she doesnt seem to have the suction to hold it and as soon as i turn my back she will drop it and start crying, meaning whenever i try to do something im running back and forth to her every couple of mins, its driving me crazy, anyone else had this problem or have any suggestions. I am wrapping a blanket over her mouth to hold it in but as its getting to the summer its a bit to warm top have her swaddled in a blanket, also i have had the doctor look in her mouth but he cant see anything out of the ordinary, HELP!!!