It seems that everywhere i have looked i can't find an answer to this!and my sweet jaheira isn't getting any better.Can someone please help me?I would very much appreciate it!

have you tried reading your journal? as soon as she's poisoned, Jaheira herself gives you clues like talking to bernard in copper coronet or checking out derelict houses in slums (which is where you'll find ployer)

Spoiler
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Go to in the slums the deserted house, in there Baror will be there. Also you can first search the Goverment buldings because you can bride his mages to help you!