Aladdin and Jasmine are usually in Adventureland between 11.30 and noon (if the weather is fine, they will be just outside the Aladdins passage attraction).
If you don't want to pay a lot of money for the Auberge de Cendrillon Princess lunch, then usually your only other option for a meet n greet with the Princesses is at the Castle stage (the exact times are posted in the leaflet you get when you arrive, or you can check the Disney site for the current times, as they should be about the same).
The princess meet n greet gets enormous queues, and you can't guarantee which princess you will meet. They change over every 30 minutes or so throughout the time span.
The princesses are also on the Parade, and if you watch the Parade outside the Bella Notte restaurant, and close to IASW, you will see them come off the float and dance. If you're in the right place, one of them may come over to say hello.
You can also get up very close to Sleeping Beauty in her little show behind the Castle. If your DD particularly likes Sleeping Beauty, this is a lovely little show to watch. Not much chance of a photo or autograph though.
Elaine