She's right.
Density isn't the enemy. Bad arrangement of dense population is.
I live in a very densely-populated city (1200/km² or 3200/sq.mi.) but it's arranged semi-sanely. Within comfortable walking distance of my home are two parks, a Daoist temple, several schools at levels ranging from primary to 2nd-tier university, two (large!) farmer's markets, three shopping centres (two of which have sizable supermarkets), uncountable numbers of restaurants ranging from holes in the wall to fancy banquet halls... You get the idea. Within 3 stops of the nearest subway station or 5 stops of the nearest bus stop all that expands dramatically. I'm not sure I could even realistically count them all except to say that it doubles the number of Daoist temples and adds a sizable Buddhist one. (The nearest church is about 5 subway stops away, maybe 6.) Outside of work (which is an hour's commute by subway and bus away) I could live my entire life without being more than 20 minutes away from my home ... and never be bored or finding myself in a rut.
I can't say the same for Ottawa when I lived there. Hell, within fifteen minutes of DRIVING I couldn't find much in most of the places I lived.