Read the caution part here...... http://nchfp.uga.edu/how/can_04/soups.html
I get a lot of info from this site. Loads of people do things in canning now and years gone by, that they don't suggest you do now.
More info here as well...
I wouldn't can milk. You could always can it without the milk and then add it when you want to eat it. I've been canning for many many years and they surely say not to can milk.