Would recommend staying at Matthieu’s apartment! It is very clean and a great size for solo travelers. He greeted me when I arrived, showed me around the apartment. He has a very detailed guide book with information on using transportation, and close restaurants and grocery stores.
It is about a 20-30 minute bus or bus/tram ride into Old Town and about a 20-25 minute bus ride to Gare St Jean.
As a solo female traveler I felt very safe in the neighborhood - would recommend!