Could New Westminster have become the capital of British Columbia? If so, there is one way to make it more of a city.
Well apparently there was a considerable amount of chicanery that surrounded Victoria being chosen over New Westminster for the capital of the united Colony of British Columbia and Vancouver Island so perhaps if circumstances were a bit more favorable things might work out in favor of New Westminster.
If New Westminster was the capital of BC, it would be the obvious initial terminus for the CPR. Though likely this would mean nothing more than an alternate route as Vancouver is a far better location and one far more profitable for the CPR let's not forget! Still having New Westminster being on the CPR mainline instead of on a spur line would be immensely helpful. New West likely would maintain a good number of the people and industries that migrated to Vancouver in OTL, though they would certainly lose some. Construction on the CPR is also likely a lot faster due to not having to worry about reaching Victoria. Work likely starts in 1872/1873 in the Frazer Canyon and is suspended until it's picked up in 1881.
I also wonder if this alternate capital of BC might mean an earlier bridge over the Frazer south of New Westminster? This would also contribute to the city's boom as the lack of a railway Bridge was the only thing in OTL preventing New West from becoming the major rail hub in British Columbia. In TTL the city might just have enough clout to get it done despite all of the CPR's shouting.
I almost wonder if wouldn't wind up at Ottawa anyways. In Upper Canada you're going to have York and an enlarged Kingston... and much of the Kingston growth comes at the expense of York. In Lower Canada you're going to have Quebec City and a much enlarged Montreal. I'm tempted to say they still might just split the difference.
Plus, the timber trade being such a huge part of the economy the Rideau canal may get built anyways.
I don't know if Kingston can steal
that much growth from York. The soil around York and the rest of Southern Ontario is some of the best of the world. You can only farm so much around Kingston...