We enjoyed staying at Manuela's house very much. It was our first time in Rome and the perfect place to stay. We came to visit the Open House of the Temple of the Church of Jesus Christ of Latter-Day Saints which is also very close. (The next ward house is just a three minute walk up the road which we were very happy about on Sunday.) Public transportation is nearby (metro and buses). All touristic places and the airports are easily accessible with that.
Manuela's little house was as described and we can recommend it. The stairs are indeed a bit steep (nothing for older or really heavy people I would say) but was not a problem for us.
Manuela's son welcomed us, explained everything and handed us the keys.
All in all we had a fantastic time.
Thank you very much! :)