What can we do if we don't trust executor to my grandmothers will?

An executor is not the executor until appointed by the probate court. Go to the probate court and request the file. You can read the will and monitor what the executor has done. She must file an inventory with the court and will need to file an account when the estate is closing to show the court where all the assets went. She must follow the provisions of the will. If she is not performing her duties properly and with expediency you can request she be replaced with a new executor.