I am a US citizen thinking of gifting stocks valued at $15K to a niece who has a dual citizenship of US and Canada. What are the tax implications for her as a residence of Canada.
There is no "gift tax" in Canada. Any resident of Canada who receives a gift or inheritance of any amount from almost any source (except from an employer) will not have to include this in their income.
Your niece won't owe anything.
However, if capital property (e.g. real estate, investments) is given as a gift, the person who has given the gift will be deemed to have sold the capital property at fair market value (FMV), and will have to pay tax on any resulting capital gain.
And this Canadian law does not apply to you, an American citizen living in America.