First idea; try looking at your max FPS located in settings. Second idea; it may be on mineverse, be patient and wait until they resolve it. Third idea; it may just be your computer?
I'm pretty sure the Mineverse server isn't that bad; it won't negate from her FPS by like 890 ;l + There's nothing that's really causing lag, yeah - the servers are laggy, but that's network. She said she used to get 900... ;l There are like 100000 things that could be wrong: Restart your computer i swear to god... it fixes 99% of my problems Reinstall Minecraft completely remove Minecraft; backup your worlds if you have any, but make sure all those MC files are gone, re-install it Kill any background processes that never used to be there... you aren't like rendering a Pixar animation in the background are ya? Hard drive, replace it is this just with Minecraft? Is your whole OS laggy? It might be your hard drive if your answer is yes if none of these work, seek a witch doctor to apply voodoo magic ur cursed
simply turn off any music, i recomend playing music on a totally different device, 2nd check your max fps, 3rd, download optifine, 4th make sure minecraft is the only app open, 5th make some space on your laptop/computer, lower render distance
it could be your internet in general xD don't visit a witch doctor to apply voodoo magic before you check your internet speed, if its too low maybe consider upgrading, or it could be your computer in general, mac laptops are not built for gaming especially the older models
3-4 FPS has no business with network, lag causes lag, not FPS drops. She stated she used to get 90 FPS, so it's not her machine in general. Macs are pretty good for MC, my 2012 MacBook Pro runs Minecraft exceptionally well.
