>>10631260TL;DR: Gura is losing networky frames when connecting to Minecraft server. Minecraft server tries to preserve uninterrupted gameplay synchronizing all the users connected to it. When one user is too fucking slow and boggles down other connected players - that lagging player is kicked. This is the same as in Counter-Strike or APEX with dude having 300ms ping being auto-kicked from match.
Proving that is fact that Gura being on the server also makes other players lag. That's Minecraft server trying to keep everyone online "on the same page" but with Gura being VERY BEHIND, it drags everyone online a bit to compensate until it can't then Gura is kicked.
Gura should check packet loss between her PC and Minecraft server, I bet she's losing a lot of packets.