It appears that the focus locked on where the gloved hand touches the blanket. If your camera won't allow you to recompose after locking focus on what want sharp would advise manual focus. Also, to avoid blur from camera shake minimum shutter speed should be 1/the focal distance of the lens(85mm in this case). Will likely need to add flash or increase iso to get the combo of aperture and shutter speed needed for the look you want.

As I look at your photo I can see that both the mothers and babies head are out of focus yet the babies legs are in focus or at least closer in focus then anything else. Aside from the advise given above I am wondering if you are letting the camera choose the focus point. If this is the case, at close distances it is almost guaranteed that the camera will pick the wrong focus point. I would suggest either picking the focus point yourself or just focusing manually until you are able to zero in on the exact cause of your blurry photos. All of the advise about aperture and making sure that you are not going in closer then the minimum focusing distance is good but here is something to consider.. If you are shooting indoors and using an aperture of f 8-11 you will most likely be at a very slow shutter speed that will guarantee motion blur. If you chooise this as a solution you will have to use auxiliary lighting. If this was my problem I would approach it by putting the camera on a tripod and shooting with manual focus with both subjects on the same plane of focus. This will pretty much rule out user error.