If she wants to live in Boston/Cambridge, she will be paying through the nose for rent. My husband and I spent a couple of years in heavily-subsidized "student family housing" and we still paid around $1k/month for a tiny one-bedroom apartment (albeit one with an awesome view of the Charles River). The same apartments now go for nearly $1500/month. Getting a place in Boston/Cambridge with parking may be difficult - there's a reason Zipcar was founded there.
Allston/Brighton is a good option. It's near the T if you want to get into Boston/Cambridge and hit a restaurant, or a bar or two, and not worry about a designated driver. (Be warned that Cambridge cops are Nazis - you do not want to be pulled over on a DUI, or even get a parking ticket, there.) Plus, on-street parking can be very hard to find.
I have friends in Braintree. It's T-able if you want to get into the city, but it's the dead tail end of the Red Line.
I have friends in West Roxbury. It's commuter-rail-able but the schools suck. (They send their daughter to private school.)
Just my $0.02 based on knowledge from someone who moved out of MA 12 years ago.
