Instead of sending shampoo, soap and cereal, I would send foil pans (all sizes) and zip lock bags (all sizes) These are very expensive. Plasticware is also expensive and terrible so if you send a suitcase full of these products that would be very useful to her especially if she won’t be very wasteful with it. Plastic plates and cups can be washed a few times before thrown out as well as foil pans but then they can be tossed and you don’t have to worry about scrubbing burnt food off of them.
One thing I brought with me on my last visit to Israel was 3 in one Purex laundry sheets. This is the most convenient thing ever. It has the detergent and the dryer sheet in one. It works really well and keeps the kids from shlepping the huge economy size laundry detergent with them to the laundromat. Sometimes the kids have to walk up and down 4 to 8 flights of stairs depending where their apartment is. So I would spoil them that way instead of shampoos and coffee.
Shoes are another thing to really consider. They walk all over and use up their shoes. So truly consider the effect on their feet. They won’t need high heels at all. Even for Shabbos unless they are in a very fancy Seminary and are in one building. Walking on the streets of Israel in high heels is very difficult to maneuver. So at least two pairs of sneakers and a few pairs of good walking flats that don’t have a very thin sole, as well as crocs or some other kind of water shoes. Rubber soled shoes are also a consideration because when it rains the streets can be very slippery.
The rules you set up with your kids should be very clear. You should draw up an agreement that you can all live with. Set up a credit card with a low limit so you can keep her on a budget and she can be financially responsible. Sit down and figure out what will be necessary and would be excessive. Discuss this with the seminary to begin with. You can go online and see how she is spending and pay daily, weekly however you want as long as she is being responsible. If you see and feel that she is being irresponsible or you see that she is using the card in areas you told her not to go, then it is time for a phone call and a discussion. Most places do NOT accept American Express as far as I can remember.
Remind your child that going to Israel is a privilege and should not be taken lightly. It is not camp and they have rules as do you. She might feel homesick and lonely but that is something she will have to work through. She will meet girls from all over the world and learn a lot from them some good things and unfortunately some bad things. She will have to learn how to choose appropriately. She is NOT leaving her family behind nor what she learned behind, she is taking who she is and what she learned with her and she should be proud of who she is and not be afraid to show it and stand by it. She is going because you trust her to be who she is and who you raised. If you didn’t trust her you wouldn’t be sending her, but on the other hand she will be exposed to many things without the safety of the family and the familiarity of her school and mechanchim that she is used to, to protect her from it. She will have to make the appropriate choices on her own even though there will possibly be some pressure on her to make bad choices. That is real life and the real world. It will be up to her to take what she learned and apply it, and remind her that her family is only a phone call away to back her up.