They're hard to compare because their speed is represented differently. Quicksilver's speed is done introspectively as he moves so fast the world slows down around him and they show the audience how he sees the world.
We never see the world from Makkari's view as she runs, we only see what it actually looks like so everything is blurring together because she's going past it so fast and she makes sonic booms and stuff and jumps hundreds of feet at a time.
QS might seem faster, but I believe Makkari covered greater distances faster as we never actually see Peter running around large areas. He runs around the kitchen and the mansion, and he runs from his house to the mansion but we don't know how far away they are from each other or how long he was running as he just showed up.
She ran from Iraq to the Indian Ocean to find Arishem and came back in a few seconds. But that was only after she ran around the world and went through that bridge in Europe I believe and she ran past the Jesus statue in Rio de Janeiro.
That'd be like 8,000km into the middle of the ocean and then she came back. So she ran 14,000km or some other ridiculous distance in under a minute if we don't take into account side trips. More likely it was 20,000+km that she ran in an incredibly short amount of time. QS has the better slow-motion speedster effects, but I think Makkari is faster. I could be wrong though as I havent' seen any calculations yet.
I can't find his respect thread anymore so I don't remember any other shows of his speed aside from the main ones.
She absolutely wins though.