Taaraa was a very intelligent woman. Baali had also accepted her intelligence and made it known to Sugreev and Raam etc. When Sugreev came again to fight with Baali, she knew that there was some strong backing after Sugreev that was why he dared to come again. She told everything to Baali also, but he didn't believe her as he could not reconcile that anybody like Raam would kill him from hiding. So he went and was killed by the arrow of Raam. 

My Note:
Taaraa cried a lot for Baali. More than two Sarg have been devoted to her lamentations for Baali in Vaalmeeki Raamaayan. Maanas doesn't give so much importance to her lamentations but it gives a good account of Raam's discourse to Taaraa, while Raamaayan has no mention of it at all.

Another incident of her intelligence may be found, when even after getting wife and kingdom back, Sugreev didn't care to search for Seetaa, Raam got very angry and asked Lakshman to go to Kishkindhaa Nagaree and remind him for search of Seetaa. Lakshman entered like a storm in Kishkindhaa in a great rage felling many large trees. All Vaanar appointed at outposts ran away in fear, Angad happened to appear there so Lakshman asked him to tell Sugreev about His coming. Angad was also scared seeing Lakshman's fury and hearing His tone. Then with the consultation of his ministers, Sugreev sent Taaraa to pacify Lakshman, which she did very well.