My AP did not have an mp3 player, but I would never have allowed that for the very reasons that has already been brought up. It amazes me that she does not understand that it is irresponisble. My AP had a big music collection, she would play cd's on the dvd player in the living room, and listening to music and dancing about was an activity enjoyed by her and the kids together. In her own time she would play her music on the radio/cd player in her room. I did deliberately not put a tv in her room, or a pc as I did not want to distract her from her duties.
With regards to computers, email and msn is such an important part of staying in touch with friends and family, so I would not ban that. She was allowed on my laptop in the evenings when I did not use it. I created a log in for her, so she could log in as herself. But, it was restricted for security reasons, she could not download stuff, etc. But she could check her email, chat on msn, gadu gadu, etc. But, in her free time, not when she was working, and to be honest, she never tried to bend these rules.
As with most relationships, the one with your AP is a careful balance of strictness and flexibility, and respect. What is important to bear in mind that this is most likely a new experience for both of you. For her, she has left her family, friends, is in a new country, and has to cope in a language that is not her own. For you, you have to cope with a complete stranger in your house, one you dont know, dont understand probably, and with a different set of expectations to your own. It is important to discuss the ground rules early. Have your expectations in wrting, much like a time table day by day so she knows exactly when her free time is, and what is expected of her.
For both my APs, I have let week one be settling in week. I have told them "Ok this week, we will get to know eachother, on Monday, we start our routine." This has worked very well.