I would like to play minecraft with my sister and was I'm LAN but she's not connected to Wi-Fi but to ethernet and I could still play with her?
That's fine. WLAN and LAN cables are in the same network. Only the type of connection is different. But it doesn't matter…
For example if I Me with her or she wants to connect with me, it always says that it would not work, we have already tried several times
What is written there? It doesn't just say "doesn't work".
Network settings check whether both networks are set to "private network" under Win… Also check whether Java is also allowed in the firewall, otherwise it won't work… Otherwise she has an IP on the PC, she has to free her world in the LAN give. Then you have to go to "Connect directly" and enter your IP: Port. The port number is displayed when you share the world in the LAN.
