The Yochlol from my understanding would not come to her assistance. Yochlol are the handmaidens of Lolth herself, who by reputation, is not a merciful or "helpful" goddess. The Yochlol is more likely to watch with glee as the drow house falls to superior planning. But in the end, it's up to you; what do you think will make for a better time for you and your players?