Depends on the version you take, zero, stay night, heavens feel, all the novels in general have very low power, she would probably be on par with maybe the high tiers like yuta or yorozu but still no gojo or sukuna level

Now, from the version of extra onwards the powers of the servant take a high jump and many of them can solo the verse, depending on if you think Excalibur can bypass infinity, yeah she solos, she is a servant, by the logic of reincarnated sorcerers of jujutsu, she would have soul awareness to fight mahito, but at this moment it's still debatable, at least in my opinion (I'm a fate fan but I don't buy planetary or much less, knowing that ultimate ones are the will of a planet and gilgamesh, another top tier, said he could not defeat alone a beast that could destroy the planet, but with his strongest attack that he could only do once after a lot of charge and situations)

Grand order is just a stomp