https://boards.cruisecritic.com/forum/114-disabled-cruise-travel/ is perhaps a more appropriate forum when it relates to cruising. (At least until it becomes acceptable to cruise with pets. 😒) There is a fairly long thread with information on cruising with service animals. It contains at least one post on the topic.
Thee CDC requirements apply to all dogs entering the US including US resident dogs returning home.
According to https://www.cbc.ca/news/canada/new-brunswick/us-border-dog-rules-disagreement-1.7262417 it may not even be possible for Canadian dogs to comply.
This may or may not be true, but given the average service life of a container ship any fundamental design change would likely take several decades to effect.
As https://www.canada.ca/en/immigration-refugees-citizenship/services/canadian-passports/processing-times.html explains actual processing times vary for each application.
Google does not allow email address changes. It advises the creation of a new address.
Once you have a new Gmail address you can change your CC email address.
You only need your valid Canadian passport to enter the US by land, air, or sea as a tourist.
It is always a good idea to check official sources. See https://ca.usembassy.gov/visas/.
Have you discussed such a trip with an appropriate person on her care team? There may be options available that do not require onboard medical intervention.
It seems obvious that your niece is unwilling to live in the real world. I imagine this is difficult to deal with. I'm not sure there is anything one can do to correct the situation but I hope you can find a solution that works for you.
Canadian citizens only need a valid passport to visit the US.
A "green card" generally refers to a permanent resident card which is issued by the United States to identify lawful permanent residents. I believe the process to get a green card is non trivial and involves fees well in excess of US$500. https://www.uscis.gov/green-card/how-to-apply-for-a-green-card
If the itinerary is round trip out of a US port and there is a single port of call the port is unlikely to be cancelled as that would make it a cruise to nowhere. Something I believe is not allowed to non-US flagged cruise ships. To do with crew visas I believe.
I'm curious how you have determined what time the ship will be using when you board. Regardless, you should use Vancouver local time (PDT). That is the time the ship will be using when it docks. It will change as it heads North to Alaska which is 1 hour behind PDT.
You can't. But you can request that it be done.
Tap / click the ellipsis (•••) in the top right corner of the first post. Select Report. Enter your request in the edit at the bottom of form and tap / click Submit Report.