Kairi Nightingale
Sounds like you need to develop the characters and storyline a little bit more to come up with an answer.
Why would the friend feel 'homey'? How are they/what type of person are they normally?
The friend, I've chosen to name her Kimberley, feels like she belongs there, as she was purposefully pulled into that world, and the people who pulled her in kind of planted it in her.
She is normally very reasonable and responsible, and doesn't really act out of her normal behavioral patterns.
Kairi Nightingale
Why do they have powers? (Both story reason and why you gave them it). At what point in the story do these powers actually come into the plot? Why would their powers suddenly come to light as they do? Do they only have powers in this dimension, or did they always have them?
They have powers because they each come from a family in the AD, and in the story, their families are magic and magic is transferred by blood. I gave them the powers because the differences between which powers they received from their families creates a lot of tension, and ends up with one of the characters almost getting killed, which is very important to the story line.
Their powers aren't all that important, actually, the importance is how they got them and from which side of the family they're on.
They're powers come to light all of a sudden, because there is a certain sort of drug in the AD's atmosphere that reacts with magic and kind of brings it to the surface, and also prevents aging.
They didn't have powers before going to the AD, but if they go back at the end of the story, they will still have powers on earth.
Kairi Nightingale
Keep asking questions and try to think things through. It may help you come up with some cool ideas for the story.