Don't know if this might help, but when trying to pair my very territorial female nigripes (who won't tolerate any other fish in her tank, except for--now--her new mate), I placed her in a breeder box that had a separate chamber with an airstone, and let her cool her heels in there for a few days. I placed the box low enough in the tank for her and the male to see each other and interact through the walls, but the female couldn't get to the male.
After 4 days with no aggression on the part of the female, I released her and watched them closely. She continued to harass the male periodically during the day (but much less than initially), and they slept together at night. The male also acted "bolder" around her and would only retreat a couple of inches, then return, rather than fleeing to the farthest corner of the tank. Since he wasn't looking tattered or stressed, I decided to let them proceed on their own and just monitor them closely.
I figured things were going well, but also that it would take a while for the female to truly accept the male and begin bonding with him. Actually, it only took a couple of days before they were not only sharing sleeping quarters, but hanging out together during the day. They spend almost all of their time together now. She still bites him every so often, and sometimes chases him back to wherever she apparently thinks he should be (often into the cave they share), and he's started doing the submission shake.
FWIW, they're both captive-bred (from Sustainable) and young. The female is about 2.5" long, and the male is about 1.25"-1.5" long. I think the size difference and the breeder box may have done the trick, because she rejected another nigripes, almost the same size as her, that I originally tried to pair her with (they actually came in as a pair, but she evidently had other ideas). It probably also helped that the female had never had a mate before.
