Prospective tenant with expired residence permit

Hi all and hope you are well. I’ve got a married couple who are hoping to rent my flat in a couple of weeks. Husband has British passport but wife has a Palestine one and her residence permit expired March this year. They are in the process with the home office to try and renew it and I’ve seen a letter from home office confirming the application. I would really like to let my flat to them, but under the Right to Rent rules am I ok?

Check with the Home Office landlord helpline.

Thanks for the advice.