It looks like out of SAN there are two C class seats avaiable SAN-LAX-JFK-LHR on 3328/22/116 on 11/5 or 11/6. Alternatively there are two C available on 11/8 on aa 512 (a class) AA98 (c class) SAN-ORD-LHR.

On the return:
11/12: LGW-STL-SAN AA135/3043
Other than the above, I'm couldn't come up with any confirmable space on the return through 11/19...unless they're willing to spend the night in JFK & catch the 7:40am non-stop the next morning to SAN.