I'm not sure you wants your daughter to be at what the locals do.
If she's car-less, she'll need to familiarize herself with Metrobus. St. John's has terrible public transit; she's in for a shock if she's used to the sensibility and convenience of public transit in Calgary. Routes and times here are generally inconvenient.
http://www.metrobus.com/home.asp
A good first day activity is the familiarize herself with the lay of the land. St. John's is a linear city, not very wide from east to west but incredibly long from north to south.
Also, coastal cities are very different than prairie ones: on the prairies, the downtown is usually at the geographic centre of a city. In St. John's, and most coastal cities, the downtown is at the extreme edge of the city along the edge of the land. There are vast parts of the city she's never going to see or need to go to.
Since she'll be on res, I recommend taking the bus downtown on her first free afternoon and exploring a bit. Downtown St. John's is very dense and compact, as old cities tend to be. It's easy to walk around the works of it in a few hours. Focus particularly on Water, Duckworth, and George streets since this is where she's likely to end up most often.
When she goes clubbing with friends, advise her not to go to Allure or Onyx. These places don't have the best clientelle and, while anywhere in St. John's is perfectly safe, they're the types of places where Girls Gone Wild videos could be filmed.
Dusk is the pretentious dance bar, VERY popular with the university students from big cities. That's a better choice. If she's more into pubs, then Christian's, and the two bars on campus (Breezeway and Bitters) are great bets.
Sundance is also very popular.
Martini Bar is a great option for a respectable young lady who still wants to have the college experience of crazy nights out.
Anyhow, back to her walk...
The must-stop spot for lunch is Rocket Bakery. Rusty van Reddick thinks it's one of the best cafes he's been to, so it's a great introduction to the local cafe/coffee culture and food scene.
http://rocketfood.ca/
For clothes, Model Citizens, Always in Vogue, and Twisted Sisters are the trendiest for girls. They're all downtown.
You can buy booze anywhere here - corner stores, gas stations, whatever else. But if she wants wine or anything hard, she'll have to go to a grocery like Sobey's.
If she's into learning a bit about the local culture, The Rooms Museum is the best first stop. There are also lots of informative signs and plaques all over the city, generally on the route of the Grand Concourse (our urban trail system - includes park trails, city streets, etc.).
For a reasonable price, you can also hire a sight-seeing cab at a flat rate. They'll take her all over the place, even to Signal Hill and Cape Spear (which are otherwise long walks with no bus service).
Beyond that, she'll find whatever she wants based on her own interests. Everything is downtown except the big box stores. Even the main sports centre is downtown. And it's all in such easy walking distance that she'll have no trouble killing a few days and discovering all sorts of things she'll want to look into further.
She'll also have easy access to a swimming pool (the Aqua Arena) on campus as well as a skating trail in Bannerman Park, so she should bring along the necessary equipment if she enjoys either of those things.
She'll also want to consider a pair of rubber boots. They're fashionable here in winter and spring, in bright colours and patterns, and VERY necessary if she's going to be walking anywhere. Even in the depths of winter, it's generally mild, slushy and wet here.
Also, the city doesn't plow the sidewalks in the winter, so people have to walk in the street.
