Minecraft multiplayer with mobile data?

Hi, me and a friend of mine wanted to play zsm Minecraft. She has Wi-Fi and I use my mobile data. But I can neither in their world and they neither on mine (our worlds are and not shown to each other) do you know why and if you can play zsm at all if yours has an internet connection?

You have to be in the same Wi-Fi so you have to be with her and for this you have to be near your router in practice so in your home or in front of it