I'll definitely be bringing Naelia in, but she might give some of your characters a hard time, since one of them was making fun of her the last time she participated in an Army mission (nothing she can't handle though, it just hasn't happened much, since most minions just accept her as one of their own, but there's always the odd exception. Though this time, she may have her trusty whip with her and even Drinch may be flying ahead, just to make sure these minions stay in line, so to speak). I was thinking that maybe Lathana's the blonde mentioned, since perhaps she did manage to escape and was captured by some of Mordor's forces, but doesn't know her connection to Naelia, so perhaps this is a way to get the minions who mocked her earlier on her side, so to speak (just an idea).
As for rescuers, I can also bring in Talina (I need some more experience with her anyway, being one of my newer characters; Elanor Starsley being the other).
Though I originally pictured Lathana as having dark hair like Naelia, perhaps their mother was one of the fair haired Elves instead of the dark haired ones, and Naelia got her dark hair from her father. As for Lathana, since she's Naelia's half-sister (same mother, different father), perhaps her father has lighter hair as well, which is why she has very little resemblance to her half-sister (other than her pointy ears, which she hides under her shoulder-length curly black hair so that she appears more human). Like Naelia's, Lathana's father might still be alive, but thought his daughter killed along with her mother, so he never made the effort to come look for her. If she survives this, perhaps she can go seek him out and go live with him, rather than continuing to rot in the Black Pits of Mordor.
He who commands the Ruling Ring... commands all