When is appropriate time?

So I’m moving in with my boyfriend this weekend. Idk how to tell my best friend without making her feel sad or something like that. She’s currently very depressed because she broke up with her boyfriend. And if I mention anything about my boyfriend she gets all sad and even starts crying. This is why i have been avoiding speaking about him to her or even mentioning his name. When would be the appropriate time to tell her I’m moving? I’m moving an hour away from where we live. She lives a block away from me and we see each other often. I don’t want to make her more sad by the news. Please no rude comments.