Andrea and her partner are really nice people, friendly and welcoming. Andrea's place is very convenient and central (very close to Gare du Nord and Montmartre), right by the Metro etc.
If you are happy with pretty basic facilities and not fussy about comfort etc this will work for you - especially if you just need a place to sleep. But be aware it's up six flights of stair to the flat, another short set of steep stairs to the loft bed. The loft itself is above the kitchen and living area, so open to noise and cooking smells plus it has a low ceiling that prevents you standing...so it is just a sleeping area not a room. The bed is only moderately comfortable and the pillow leaves a lot to be desired.
Having said all that it is quite cheap for Paris and you get what you pay for.