Is the supplication of a mother accepted against her son who never prayed, severed family ties, consumed the orphan's wealth, slandered chaste women, and committed many evils?

It is permissible to supplicate against an oppressor, especially if their oppression has become extensive. This permissibility includes both the oppressed and others, due to Allah's saying: "Allah does not like the public utterance of evil, except by one who has been wronged." This is also indicated by Abu Hurayrah's hadith (definition) concerning the complaint about a neighbor. As for a mother's supplication against someone unjustly, it will not be answered because it is considered a sin.