I finally got around to this and it's working great. Thank you.
If I wanted to route all internet traffic through the site-to-site VPN, is this article still valid?
https://doc.pfsense.org/index.php/Routing_internet_traffic_through_a_site-to-site_IPsec_tunnel#Configure_outbound_NAT
At the end, it says to modify the Outbound NAT at Site B (where you want your Internet traffic to exit), even though you want Site A to use the Internet at Site B. Is that still correct?
Edit: This worked perfectly, I missed where it said to add a route of 0.0.0.0/0 at Site A, thus my confusion.