HELP! Sewer Backup and Threatening Tenant

[Mindy Jensen]

OK, this is for one of our developers -  the people who keep this site up and running.  She would REALLY appreciate any advice you can give. She's a newer landlord, so go easy on her.

She rented her property to a new tenant who moved in last month. The dishwasher broke and the sewer backed up, all in one month.

Sewage backup is being dealt with, the dishwasher is too.

Tenant is mad, understandably.

Tenant is saying she does not feel that she should pay the entire month's rent since she can't use the basement. 

Rent is due on July 1, landlord said she would give until July 5. (She's learning, be nice.)

Any advice for our landlord developer?

I'm not sure the landlord tenant laws for CO as I am not a landlord here. Tagging @Bill S. because he runs the Denver landlord meetup and definitely knows more than I do.