When I say build I don't mean she builds things. Jezera is the one who negotiates alliances, puts spy networks together, and so on and so forth. She's still ruthless, she's still a killer, she's still a petulant brat but she recognizes the need for more than just wanton violence and devastation. Jezera is the one who, once the dust settled from Rowan conquering the realms for them, would set about rebuilding the necessary infrastructure to rule. Jezera, when not showing herself as an easily offended child, is the one most likely to hatch a plan, put that plan into motion, and get the best result. She may not be hammering nails into boards, but without her there would be absolutely no framework for Andras to work in and he'd probably never ascend to anything more than the leader of a small territory of orcs that would eventually get routed out by a hero.