Minecraft: Why does my opened to LAN world not show up in my other laptop? [duplicate]

I am really annoyed of this problem. I have did everything that everyone said, like run the Command Prompt and find the specific IP (they matched), restart Minecraft, uninstall all other Java versions unnecessary, I have turned off Firewall, and other stuff, but it STILL does not show up. I am on a wired connection (I use a normal computer with a CPU on it, obviously) and my cousin is using a wireless connection. We ARE on the same connection, just the difference of having wired and wireless. Does that difference affect the problem I'm having now?

And to all the other people, I know this might be a duplicate, as other people have asked similar questions, but I tried the answers people gave to them, and those still do not fix the problem.