Unable to connect to world

We are both using, Minecraft windows 10 edition, the one with xbox live

So we use xbox live to connect and play with each other. Issue is that wheever we connect to one of the worlds i created, we are able to connect and play with each other. But when I try to connect with her, its always unable to connect. We have tried everything, things like invites and stuff but it will always include unable to connect.