>>692188She's probably a better fighter than Blenny, much more skilled which will give her the advantage, so I'd give it to her in most cases unless surprise demon shenanigans are at play.
Gretel's training was mostly in hand to hand combat and melee weapons, which is her preferred combat method, but she is entirely capable of using firearms and explosives if needed. How skilled in firearms is T.T? Gretel would probably just use the guns and explosives to allow herself to get close enough to T.T to make it a hand to hand brawl if she could.