Need a little clarification: this person takes all loans aps of people who think they are applying to your bank?
Ignoring the fact that she is sitting in your office space, she is acting as a broker and there is not necessarily anything wrong with that provided that the firm is licensed as a broker (assuming your state requires that - most do).
Is the bank paying for these broker services?
It is common for a broker to order the credit bureau, take the application, make disclosures (including required broker disclosures), etc. and in return for that get a fee from the lender.
The payment must be for work actually done, not just for a referral.
The use of office space adds another dimension which can be okay under RESPA as long as she does real work and it is not a sham to pay referral fees. That doesn't sound like an issue.
Given that she is using bank space, working on bank premises, you really need to discuss this with legal counsel and have a documented contractual relationship..who does what, how much payment is and what you are paying her for, how the space is paid for, the bank's expectations including fair lending expectations, what the underwriting terms are that the bank will accept, and so forth.
At a minimum this relationship must be formalized. You should review this situation with legal counsel as soon as possible.