cooker or canner, it sounds like it's just a terminology difference. The 15 minutes at 15 pounds sounds like just what you need. As for the baby food jars, what lids are you trying to use? I couldn't imagine being able to successfully reuse the original lids and I didn't think regular canning lids/bands would fit.
You're probably better off getting regular Mason jars/bands/lids for canning your wort. I usually use a mix of quart jars, pint jars, and "jelly jars" (4oz). I also "can" a couple of extra of the 12ml vials I use for slants with just 10ml of wort in them. That way, when it comes time to grow up some yeast, I take some from a slant and put it into the vial (with 10ml), next day (or two) dump that into a jelly jar of wort, next day dump that into a 500ml flask, add a pint jar of wort, and stick it on the stir plate. Finally, dump the 500ml flask into a 2L flask, add a quart jar of wort, and stir plate away.