Is a woman's correspondence with men who are not her mahram—including one she thought was a healer but turned out to be a charlatan, and another young man to clarify medical information—considered a breach of her covenant with Allah not to correspond with young men except on matters of English language and computers? And does this imply that she has sinned and become a hypocrite?

Correspondence between young women and foreign young men, without a valid need, is wrong and a pretext for corruption. You must repent to Allah and offer an expiation for breaking your oath to abandon the conversation. As for breaking the covenant with Allah, the more cautious approach is to offer an expiation for an oath, as contracts and covenants necessitate a second obligation. There is nothing in this sin that falls under hypocrisy; rather, repentance is obligatory with its conditions: abandoning the sin, regretting it, and resolving not to return to it. Indeed, one who repents from a sin is like one who has no sin.