What to do when you know that there will be an extra guest?

I had a booking from a woman last month. She booked the room for her former boss and his wife, i just knew this piece of information today, however the room is a single room and it is only for one guest.
The confirmation letter is only about one guest will be checking in, and I just knew that there will be two guest, and
she asked for an upgrade for no extra cost, which is horrible. She even asked me to allow the elderly to sleep on the couch, which terrifies me.

After a very long explanation of my rules, she is very angry and claimed that she has booked an entire apartment for two people instead of one person.

She just cancelled the resevation and will this affect my click rates???

No it shouldn’t since she did the cancelling. It would have if you had cancelled. I am betting that you are better off with the cancellation than dealing with the headaches of this group.