JAD did a good job covering a lot of the info.
You need to NOT live in Boston (or Brookline or Watertown)!!!! She will NOT be allowed to "carry" even if issued a resident LTC by those cities/towns. Look for housing in Arlington or Quincy (maybe as <25yo get restricted LTCs there too last I knew), easily commutable, cheaper rent and less hassle getting a LTC.
She should NOT mention that she's a student when applying or may well be denied as a Non-Resident. I have a friend who rented in Quincy from VA, had moved to MA for graduate school and was able to receive an unrestricted LTC.
NR LTC is a nuisance and no guarantee of getting unrestricted (have to have articulable reasons beyond average citizen why you are at risk), expensive as well and have to go to NH to buy ammo.
She'll need to take a course given by a Mass State Police Certified instructor (I offer those courses), pay $100 application fee (Resident good for 6 yrs, NR good for 1 year). If a resident of Boston/Brookline she'll have to take the Moon Island test (revolver, 30 rds, score 210/300), no other town requires this. Application process varies by town from 1 month to 6 months, NR LTC process takes 4-6 months as of now.
Illegal to carry a firearm on school property (includes grades 1-12 and all colleges), and most also ban OC/sprays as well (legality is questionable without a letter of authorization from the school).
No so-called "Assault weapons" or large capacity mags (unless made on/before 9/13/1994) are legal in Mass. AG has declared all ARs and AKs illegal except those made on/before 9/13/1994 and there are pending lawsuits about this, however it will be 3-5 years before these get adjudicated. Boston has its own AWB, with NO grandfather clause mags/guns (listed models) allowed in the city and its neighborhoods (e.g. Allston, Brighton, etc.).
Go to NortheastShooters.com and read the stickies in the Mass Gun Law sub-forum. I also have some other legal info in my own training sub-forum there where I locked the threads so you can easily find the real info without sifting thru 100s of irrelevant posts. I am known as "Len-2A Training" on that forum.
ETA: In MA to get a LTC one must be at least 21 yrs old. To possess OC (no permit needed) one must be at least 18 yrs old (15-17 yo with written parental permission can get a restricted FID card to possess OC). Since FID cards are only good for OC and low-capacity long guns, they are useless for self protection.