We arrived Paris via Gare Du Nord. We tried walking to her place. Estimated around 20-30mins. There is a very steep slope up to her place * however her place is right at the bottom of Sacre Coeur*
It's quite physical challenging as we happen to have 2 prams and a wheeled luggage. The place & location is more practical for singles/young pple. Those who have families, not advisable thou. Suitable for backpackers as you need to climb up steep stairs to the 2nd floor