I've stayed at Elena's for almost 4 months and it's been a great experience !
Elena is a kind and responsive host who helped me whenever I needed anything.
The house is well located if you need to go to Harvard, Boston College, or Boston University (you are at a 10 minute-walk from the closest green line station and less than 5 minutes away from several bus lines).
The neighborhood is peaceful, I've never had any issue walking around, even late at night.
If you need to stay somewhere to study for a few months as I've done, I totally recommend Elena's place !