Without a lawyer, it is extremely hard for you to get the answers you are seeking. You need some type of evidence that there is something of value taken from the property. My suggestion to you is to demand an accounting of all personal property in the house and request that you enter the premises only to take photographs of the home. Make sure it is in writing to the lawyer. Then after you have pictures, if something comes up missing you have evidence that it was in existence at one point in time. Time is of the essence with this. This is why I recommend all of my clients to walk around their house before they die and take pictures of their belongings. This eliminates the dispute at a later date. I wish you luck.
I agree with Mr. Sivia that it is probably worth you investing in a good probate attorney.
One step you might want to take is to request that the court supervise the administration of the estate. Depending on how the will was written, you may have the right to involve the court in that process. Keep in mind this will increase the expenses of administration, so if there are not many assets it could have a significant impact on what you eventually receive as an inheritance. However, if you feel the executor is not doing her job properly this can be a quick way of getting some cooperation.
As one of the heirs, you have the right to an inventory of everything owned by the estate. When families get along well, the inventory does not usually list every item of personal property in the house (usually that gets divided up informally). But when there are divisions in the family like you have, a written inventory can be very important to make sure you know the extent of the assets.