I would tend to go with the Canon beacuse I have confidence it would be a good camera. The other two are probably just as good, however. I just view Sony & Panasonic as Electronics companies, not camera cos (Yes - I know they both have camera lines now). There are good websites for example for canon users, and I'm not sure there are such dedicated sites for those other brands.
But most importatnt I think, and what was the deciding factor when I bought a P&S, was to just try them out. Go into a store & hold each one, try to take pics - whichever feels the most comfortable & seems easiest to use for the intended uses is the one to go with. There are just so many choices, studying too much will drive you crazy.
Like they say: get to a camera store, and "IF IT FEELS GOOD, DO IT!"