Is it permissible to combat sorcery with sorcery against the one who performed it, especially with her continuous harm and blackmail to quit work?

One must be cautious of accusing others of sorcery without proof. The fundamental principle is to have a good opinion of a Muslim, based on the Almighty's saying: "O you who have believed, avoid much [negative] assumption. Indeed, some assumption is sin."

If it is proven that the woman engaged in sorcery or sent offensive messages, she has committed a great evil and manifest injustice, and has caused extreme harm. It is obligatory to advise her, remind her of Allah and repentance, and seek forgiveness from the aggrieved party so that she does not incur the threat of the verse: "And those who harm believing men and believing women for [something] other than what they have earned have certainly borne slander and manifest sin."

Sustenance is solely in the hands of Allah. It is not permissible to seek sustenance through forbidden means like sorcery. If the intention behind counter-sorcery is retaliation in kind, it is not permissible because sorcery is forbidden due to Allah's right, and lying is forbidden. It is not permissible to commit forbidden acts, even in retaliation, as clarified by Ibn Taymiyyah.