I absolutely love Vancouver. I've been three times but stayed with family so I don't have accommodation recommendations.
If you are an active sort of family, hiring bikes to cycle round the sea wall (Stanley Park) is a lovely way to spend time.
Grouse mountain is good for walking and views and seeing bears (in captivity but good-sized enclosures!)
There are some fantastic beaches in and around the city. I love Kitsilano (a bit of an old hippie area) in particular. There's always lots going on there and it's really pretty.
The last time we went, we did the 'Sea Safari' from Horseshoe Bay, which is a ride on a pretty fast speedboat with some slowing down to look at seals...and expensive waterfront properties! There's also a lovely restaurant/pub at Horseshoe Bay, whose name I've forgotten but it's a very small place so you might stumble across it anyway.
If you are there on the 23rd, 27th or 30th July, then you're really lucky because those are the dates for the 'Celebration of Light', which is the most fantastic firework display I've ever seen. You can watch it from English Bay.
Bowen island is lovely for a visit too.
I'm so envious, you're going to have a fantastic time 😀