“This person said…” Did they SHOW it to you? Contact the state board of real estate and file a formal complaint AFTER you see the lease.

ummmm…I do not know.

It is the broker that is in trouble though, they have legal responsibility when their agents do illegal things.

If you suffered some sort of loss you can sue, you would sue the broker.

Either way you turn them into your states real estate board. It sounds like they may be committing fraud and double dipping on the rent (collecting more then you know about and being paid by you).

It depends on the lease you signed. Did it include language that prohibits a sublease? Because unless subleasing is specifically prohibited in your area then it’s probably ok. Otherwise, why would you assume it’s illegal?

Sure. She could lose her license, or have her licenses suspended, and/or be fined.

Each state has a regulatory department overseeing real estate agents. Find yours, then ask how to file a disciplinary action.