Level five, cleared out the Mines and looking for bandits. Finally hit on the Fiendly Arms Inn to get Jahiera, and she wasn't there. Does she respawn elsewhere?
"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." -Albert Einstein
If you tell Khalid and Jaheira that you don't want them to join when you first meet them, I don't think you get a second chance - like Montaron and Xzar. Also, if Jaheira left your party because of your actions, you can kiss her goodbye - she'll never be back.