Do i have the right to see the will?Do i have cause to consult an attorney now, or should i wait until after my mother is dead?

My mother was diagnosed with lung cancer 10 months ago. She moved in with my sister in Wisconsin to be close to where she would receive chemo/radiation treatments.Despite treatments, the cancer has spread to her brain, as well as elsewhere, and she was given two months to live. When my mom moved in with my sister, she gave me a copy of her will, which listed me as executor and POA for her financial and medical matters. As it is nearing my mom's death, i called her lawyer to ask questions about my duties. He woud not say anything except that the will had been changed. I questioned my sister and she admitted that the will had been changed recently, and her daughter was given my role. When i questioned my mother, she seemed confused that i was not still listed.I am afraid that my mother has been manipulated into changing her will. Since my sister has seen a copy of the revised will, i thought it only fair for me to see it as well. I have requested they send me one.