If Candra gets in a TK assault at the very beginning of the fight, it would force Jean to put all of her concentration into her TK to try and combat Candra. This would leave Jean nothing to spare for a TP attack. Since Candra is a much more powerful telekinetic, she overpowers Jean in this scenario. On the other hand, if Jean gets in a TP attack at the very beginning of the fight, I have not seen Candra go up against a telepath, so I don't know what her TP defenses are.
That said, Candra has also displayed both TP and pyrokinetic abilities, though the upper limits of these abilities have not been defined in canon.
I give the edge to Candra and here's why: of both women cut loose with their powers in the first split second of the battle, Jean dies from Candra's TK abilities. Since Candra is an external, meaning an immortal mutant, she will survive Jean's mindblast and eventually recover from it.