First of all, the Wireless Mac Filter is not what you are looking for.
You do not want to specify IP addresses, because those can change every time the PC is rebooted. This could be what happened and why the father was blocked instead of the daughter.
Access Restrictions, by time of day should do it. The fact that your neighbor was blocked instead of his daughter could also mean you just blocked the wrong MAC address. If not specifying any IP addresses doesn't do it, then, try blocking the other MAC address?
As for the time of day, if you specify 6 am to 11 pm, you have blocked access for the entire day, from 6 in the morning until 11 a night. It allows access from 11 pm until 6 am ... Not quite what you wanted.

This should work: Define two policies ... Select "Deny" and specify her MAC address for both. Set the time from 11 pm to 11:55 pm for one policy and from 12 am to 6 am on the second.
I tested and this is accepted by the router. It does leave a 5 minute access hole, from 11:55 - midnight, but if it works, it is likely the only way to do it.
Let me know!