The above answers have covered a lot of important territory but I have a few tips to add:
I am not sure at what level of Spanish your daughter is at, but even if she has a fairly good command of the language, there are bound to be irregular situations where she will need to communicate and wont have the right words to express herself. I am conversational in Spanish, but that did not help me at the pharmacy a few months back, when I was very sick. I didn't have access to the specific terms to communicate my symptoms and it turned into the least fun game of charades ever.
The best safety advice I can give is, that it's not as much about preventing things from going wrong, because things do go wrong and thats life - it's more about making sure you are going to be fine when they do. The best offense is a good defense, and more things like that.
Herein lies the beauty of THE LIST:
After having lived and traveled to many countries where the language is not native to me, I have learned to plan ahead for these language issues and general life fails. Have her make up a master list of the most important emergency words and phrases in Spanish - such as names of common medications or over the counter drugs, (Ibprofeno) how to ask for medical attention, or how to explain if she has any allergies or special needs. For example, if she has a tendency to get sinus infections in cold weather or has a bad case of shin splints from playing sports, make sure she has anticipated exactly how to explain this to a pharmacist or doctor (or as the case may be with the later, a shoe salesman).
In terms of everyday life, this list should also include how to explain in Spanish that she feels she is uncomfortable, is being followed or is unsafe, and perhaps most important of all - her address (How to pronounce correctly) and how to ask for directions back home. Yes we all have smartphones, but you should never ever rely solely on a phone to get you to your destination or home safely, or assume it will save the day. I cannot stress this enough. Your phone may die, be stolen, or get lost, or just not work right (all of which has happened to me) so you need a backup plan. The list. This trick has saved my life before. In addition to the above, the list should include the names, numbers and locations of the city's police station and hospitals, contact details for her program advisors, and the local 911 number. It may sounds like overkill, but you'd be surprised what panic can do to destroy your ability to communicate in a foreign tongue. Tell her to keep this paper on her at all times.
On another topic, being mindful of pickpockets goes beyond just being aware and staying sharp. Make sure she brings a sturdy/purse bag with her, that closes securely - preferably with a zipper. Bags that have straps across your body are the most secure and she needs to ensure that the bag is always towards her front and not behind her. When walking around the city, she should wear less jewelry and be sure not to flash around anything expensive (her iphone) as it will make her more of a target. If traveling anywhere on her own, she should never listen to music on headphones as this likewise makes her a vulnerable target. The moment she arrives to her housing arrangements, she should take everything valuable out of her bag that she possibly can. This means leaving the passport, credit cards, extra cash, photos of the family dog, and all ID's except the one she needs that night in a special drawer at home. This way, if she is a victim of pickpocketing, it will not be the end of the world. Have her keep a bit of money in a separate pocket of her bag or as my friends and I do here in Buenos Aires, inside of her shoe. This way if anyone steals her wallet, she will still have money to get home.
Last of all, tell her not to talk to homeless people or pet the dogs on the street. You may want to help or offer money, but they are dangerous and if you interact with them they may take you for a target. I am an animal lover and have had to learn the hard way to stay far away from strays.
All in all, it will be a beautiful and life-changing experience and I wish you both the best! Her program will have things very well in control and will be able to aid with any problems she encounters.