Depends on what percent your jiggs is at at the time of the edgeguard against fox.
If you're above 50-55% or so, or if you're near their respawn point, a lot of the time it's just better to get the edgeguard rather than resting them only to have them respawn and Usmash-kill you. If they're recovering with forward-B, D-tilt them if they're aiming at the ledge; if they're aiming just above the ledge then throw out an Nair, this'll knock them below the stage and you can just Bair or soft-Fair them to death without giving them a tech opportunity.
If they recover with Up-B, it really depends what % they're at and how well you can aim moves at fox's UpB without trading hits. But if they aim at the ledge then usually Dsmash will work best (even though it usually ends up trading hits, so if fox is at low% jiggs might get knocked too high to punish the next Up-B attempt). If they aim high, just wait to Bair/Uair **** them back off lol, or space a Fsmash if you know it'll kill them.
If you're at really low percent though and the opportunity arises (which usually means the fox either sucks or fuked up his spacing bad) then by all means rest away, lol.
King Out