Same age as our Gkids and they were here last year so we can certainly pass on a few ideas when we know what the interests are. Here's a few.
Beacon Hill Park- Petting zoo, water park, playgrouunds, small zip lines, otters (maybe) beachcombing, tidal pools, Cricket match !
Fisherman's Wharf- houseboats, seals, otters, fish & chips. Ice cream.
Inner Harbour- buskers, magicians, jugglers, acrobats. Native arts.
Government Street- Souvenirs, Ice Cream (Chocolat Favoris!!! ) Shopping Mall.
Chinatown- Restaurants, secret alleyways!
Around Inner Harbour- Royal BC Museum- (a must see) Mammoth, beach, forest dioramas . Victorian town reproduction Galleon. etc IMAX.
Miniature World- battle scenes over the ages, doll houses etc.
Bug Zoo- never been in!
Around town- Two castles, one where they filmed the X Men series and Deadpool?
Butchart Gardens- Carousel. Flowers, live music, fireworks Saturdays July & Aug)
Beyond Victoria Lotsa stuff!!