No, I don't know what you mean by your "well". Do you mean will (your legal document saying who your stuff goes to when you die)? If you do then your sentence would be: "When I am dead, my wife has the right to be the executive of my will."

A well is a hole in the ground. You take water from it. "Upon my death, my wife shall be the executor of my will." The deceased's will describes what shall be done with the deceased's estate (assets and possessions).