Originally Posted by euro
Thanks for the explanation! I'm thinking that the OP wants his niece to be able to harvest the tax deduction instead of him, ......
Probably, so the OP is really overthinking this.
Pretend niece is in 25% marginal tax rate, and give her 25% of the funds in the will, and give the charity the other 75%.
That way both benefit, and it's simple.