Suspect yours is Pathfinder (DTM will know), as probably too new for SDD.
In the case of SDD, its a free download from JLR, but needs a login. I know there are ways around the login, but I think such bypasses are at best, flaky. Suspect Pathfinder will be similar, though I've never used it. SDD is, err, "quirky" in the way it works, and in the case of her XE, there is no direct option to clear any codes.
Away from dealer level diagnostics, iCarsoft are probably the most popular on Jaguars. Obviously can't do everything that the dealer stuff can do, but can do a lot more than just a generic-ish OBDII as its geared towards the marque its sold for. Probably looking around £150-£250 for a single marque model, depending on which one you go for.