Re-rewriting my future

A girl wakes up to her everyday life but feels like something is wrong and out of place, oblivious to the fact that this is not her real life. As she starts her day, she starts getting flashbacks of random people who talk to her like they know her and realization strikes her that she is dreaming of an altered version of her life. As her 'dream' family interact with her, she feels like everything is automatic and familiar. Her dream life feels more like her own and her current life feels odd but maybe, more desirable?..... How did she manage to alter her life? And if she finds out how to go back to her old life, will she want to return?