In Jain ethics, oral sex is not considered a practice that supports brahmacharya or restraint. For a Jain layperson, the ideal is sense-control, moderation, and avoiding activities that increase lust and attachment.

So, from a Jain dharmic point of view, it would generally not be encouraged for Jain girls or anyone else.

A simple Jain understanding is:

• For monks/nuns: strictly forbidden.
• For householders: sexual conduct should be limited, disciplined, and within marriage, with restraint.
• Anything mainly for sensual pleasure is usually seen as moving away from Jain values of brahmacharya, ahimsa, and aparigraha.

If your friend is asking from a religious standpoint, the answer is: No, it is not in line with Jain conduct.