Which school is your daughter going to, if i may ask? I went to temple university in philadelphia which is known as an area for high crime, however the school is known as one of the safest campuses in the country. I never lived on campus so i traveled through a ruff area to get to and from school every day. I never had any problems. The campus is lit VERY well so you're never in a dark spot. Like someone else mentioned, there should be an escort program offered, and it usually goes something like 'dial *11 (or whatever number) from any campus phone to contact the escort service, and they will come get you/walk with you to where you need to go. I never used the service, however I would advise that if there is a time when your daughter feels unsafe, to use the service. Campuses also have a blue light service type thing, wherever you see a blue light (or red or whichever your school offers) there is a phone that will connect you straight to the campus police. They are usually ALL OVER campus. Tell your daughter to be aware of each blue light for the areas she travels, also tell her not to walk the same path every day, sometimes this can be a problem (if someone sees her walking the same way every night, it makes her more accessable and predictable). If your school has their own police department, this is a good thing. It means they have a quota of how many police need to be on duty at one time, and that the people working for them aren't just security guards that can't carry a gun, and might not have the experience or abilty to manage a situation that might be dangerous.
I never carried mace/pepper spray, but if your daughter feels more safe and confident in carrying it, then you should get her some.