The place is easy to reach from Linate. Get your bus ticket from a machine outside the airport (you can get all kinds of tickets, including the ones valid for 24h or 48h), take the bus to Cinque Giornate and change to tram no.9 and stop at Via le Piave. Christiana wasn't there to greet us but keys were easy to get from the café Bixio across the building (For breakfast, there's a special price for Christiana's guests at this café. We didn't try it but maybe you should.)
Christiana sent us messages regularly to make sure we had everything we needed.
The room is nice and clean. We appreciate the private entrance, so we won't have to disturb Christiana's family. The bed is comfortable. There was a bottle of water, tea, and coffee, water heater and also an adapter just in case you need it.
There's a big supermarket at Via le Piave not far from the house. They also sell ready to eat dishes, that we often bought for our picnic between visits.
Don't forget to try the gelato from Gelato Giusto, Via San Gregorio, 17. It was no. 1 on a list of 25 best gelatos in Milan, and it's only 13 min walk from the house (1 km).
We had a very nice stay at Christiana's place!
Tips: If you want to see The Last Supper, book the tickets three months before the date that you choose, or you'll have to pay much more from agencies.