The actions that you have described fall under the category of zina or fornication. Zina is not simply intercourse; there are steps prior to it which is also referred to as akin to zina. The Prophet (peace be upon him) said, "Eyes fornicate; the fornication of eyes is lustful looks; ears fornicate; fornication of ears is hearing; tongue fornicates through speech; hands fornicate by holding; feet fornicate through walking; heart fornicates by lustful thoughts; it is consummated by the private parts."

In light of the above, she is undoubtedly guilty of transgressing the limits of Allah.

It is best for her to put a stop to this and ask forgiveness of Allah through sincere repentance. Otherwise, she is risking her faith and honor. Fornication is undoubtedly a grave sin.

For further details, you may consult the following answers.

• What is the punishment for adultery? How can it be death, while Islam teaches forgiveness, if you don't give them another chance? Doesnt Islam teach that God is the most Merciful?
• My son asks me for proof when I tell him he cannot have girls for friends, for purposes other than doing school work, or dealing with co-workers for the matter of business, if no isolation is involved.