@Justin7
Yes well that will not work since you have your TPLink connected on the LAN port (as an AP only). The parental control function requires traffic to go out on Internet via it's firewall. This you can do whilst maintaining pfsense as the main firewall but it means double NATing...
What type of control are you trying to enforce? If it's access to specific sites or applications you could take a look at AdGuard Home. Then you go back to using pfsense as the DHCP server and hand out the IP of AdGuard as your DNS. And change the TPLink into a simple AP... I'm sure you can use some of the access control functions still. Perhaps schedule wifi access??
But in AdGuard you can set and block not just Ad's, malicious sites etc, but a whole range of applications as well. The App blocking is very simple to use with a nice UI and then the ability to set a schedule for the blocking.
Then there is pfBlockerNG as a plugin for pfsense.