Your wife's visa will expire either 1 year since her latest medical exam, or when her passport expires; whichever comes first.
To get a full passport for your baby, your baby will need to get a Canadian citizenship certificate. However I believe it takes around 9 months for a citizenship certificate to get processed, which means getting your baby's *full* passport will take at least that long too to be issued. Instead, what you can do is apply for your baby's citizenship certificate (just contact the Canadian embassy in Vietnam to get instructions on how to do that), and then get a *temporary* passport (it only has 8 pages and is valid for only 1 year) for your baby. If I remember correctly, it takes up to 1 month for a temporary passport to be issued.
Good luck!