Take a summer job now. Work as much as possible and when she gets to Israel will have a sizeable amount of $$ to spend on going out and having fun. Its so worthwhile
Take a blanket/throw to put over your bed as everyone comes and sits on your bed
A rug to put on the floor next to your bed
A mirror you can put on your bookshelf next to your bed or hang up in your room
Long skirts, thin clothes, its hot…
A list of people you can call to stay at them for Shabbos, you will need this when you get there!!
A bag for your stuff for when you go away for Shabbos
A warning that contrary to all the hype, Sem is not 100% of the time ‘AMAZING’ like people say it is, there are good days, great days, but some days are ‘ok’ and some days may even be bad, its normal, overall the experience is amazing but be prepared for some normal, ok ish times too