Generally speaking, an aunt has the same right to claim a child as a dependent as a biological parent, they follow the same set of rules.
Those rules are, wherever the child physically lived more than half the nights of the year is the person who can claim the child as a dependent. For a child born during the tax year, the qualification is based on where the child lived the greater number of nights.
The details of exact birthday in specific year don’t change the rules, they just make it easier for us to give you an exact answer. If you are filling out a 2021 tax return very late, then you would consider where the child lived the greater number of nights between January 1 and December 31 of 2021. If you are asking about tax year 2022, which you will not prepare your tax return until February upcoming, then you would consider where the child lives the greater number of nights during 2022.
