Though Ramayan is the story of Ram, the epic is also well knows for some of its female characterisations like that of Sita, Kaushalya and even Kaikeyi. But there have been some lesser known ladies who have not found much mention, even when characters like Manthara and Shabari find some mention and attention.
Popular depiction of Trijata is an ugly ogress; however, Vibhishan is not shown as a demon. This is probably because not many are even aware of this relationship. Also, as mentioned earlier the depiction of rakshasa and rakshashi was always dark, red-eyes, disheveled hair, horns, et al. The same depiction has stayed on with Trijata too, though Vibhishana is never shown as one. Again this can be attributed to popular perceptions.
Finally, why were characters like Urmila and even Mandodari (Ravan’s wife) not given their due attention? Many a times it has been seen that at the beginning of the plot, a number of characters are drawn which gives it a feel of an epic. Like in all epics, besides the main plot, there are sub-plots and many side-plots. This is like the tributaries of a main river, all converging into the main river. Though the author sets these characters with a set of ideas, in due course, ends up focusing only on the main characters or future characters and leaves a few by the side. This leads to some well-begun but half-baked characterisations in due course of time. Urmila was definitely one of them.
Another reason could be that these epics belonged to an oral tradition, where the stories were related orally over generations. As it happens many a times, the narrator ends up focusing on some and at times neglecting some characters, till they end up being part of the cast with no major contribution in the epic. The narrators perceptions take precedence.
However, Urmila’s contribution in terms of her ‘sacrifice’ (a virtue in Indian culture) is of epic-proportion and thus warranted a discussion. As far as Trijata is concerned, she is mentioned for her strong characterization (remember she warned Ravan about the impending disaster) and her staunch belief that Ram would come to save his wife and her interpretation of her dreams. She was also a strong support-system to Sita during her most trying times in the epic.