Is the supervisor of an Islamic section in a general forum that includes forbidden artistic sections sinful merely by her supervision, even if she only participates in the Islamic sections, and should she relinquish her supervision?

There is no harm in remaining in the Islamic section of the forum, provided that it does not lead to evil or assist in a forbidden act. It is obligatory to advise those in charge of the forum of the necessity of deleting everything that displeases Allah, and to advise the forum's visitors by explaining the impermissibility and danger of objectionable things, based on the Almighty's saying: (And let there be [arising] from among you a nation inviting to [all that is] good, enjoining what is right and forbidding what is wrong, and those will be the successful) and on the Prophet's (peace be upon him) saying: "Religion is advice."