Will vs IRA beneficiary which is right?

What is the name of your state (only U.S. law)? Massachsuetts
My sister passed away recently and I have yet to go to her lawyer to settle her estate. She left to me her house, car and a small savings account. I have a copy of her will and in that it states that she wants me to have the house, car, saaving account. The will also states that the remainder and residue of her estate will be equally divided between my other sister and myself. Here is my question: She also has several IRA accounts. Two months before she passed she changed the beneficiary on her IRAs to me at 100% primary because I was the one who took care of her for the last two years of her horrible illness and have fallen in debt because of missing so much work. I am also listed in the will as the executor of her estate. What happens to the IRA accounts? Am I still the beneficiary 100%..or are they split 50/50
Thanks

The IRA beneficiary designations prevail. Contact the IRA custodians for forms and instructions.

And remember that, if these are traditional non-deductible IRA's, distributions will be taxable income to you. If it is significant money, you might want to have a brief consult with a tax professional on your options.