The apartment is a few minutes away from the Nyhavn, very central in a lovely street.
Ruth is a great host!
A few very nice restaurants just 1-2 minutes walking. The flat itself is cosy with a comfy beds.
High floors with steep, a bit challenging stairs - if you have a heavy luggage, climbing the stairs might be tiring.
The apartment is well equipped.
If you have any troubles with sleeping while there are any noises, consider ear plugs as bells from the church are audible.
I recommend staying at Ruth's apartment and if you prefer lower floors, there are more apartments of her in the same building :)