There are two methods you can use to try to have this timeshare reclassified..
Obtain a written comparative market analysis from a real estate broker who specializes in timeshare resorts- showing that the expected resale value is basically nil.. I've prepared hundreds of these for both individuals and for law firms (I charge $49). You may be able to find a timeshare broker who will give you a formal written CMA for less or even for free. Since the timeshare is located in Nevada, a broker licensed in Nevada may give you a better chance of acceptance by your case worker.
You'll need to submit this document to the case worker, and hope they see reason. Most do, but occasionally you will deal with one that insists a certified appraisal is required.. If this is the case, you then have to pay for a certified appraisal (approx $400)- but you need to be sure the individual you hire is knowledgeable about timeshares.
Even if you have to go the appraisal route, it is still easily worth the expense if it makes a big difference in the evaluation of her assets. Like anything involving government bureaucracy, you'll have to be willing to keep pushing- but these situations can be resolved.. They just take time and persistence.
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For others who are reading this discussion.. This situation is easily avoided with simple estate and probate planning. Take an hour to discuss your timeshare holdings with your family attorney and it can save you and your family countless hours of frustration in the future.
It is a relatively simple process to create a trust or an LLC where you can place all of your timeshare holdings. (Have the attorney discuss the process with the resort management company to ensure they are aware that this "deeding" is being done for estate purposes and is not a resale transfer to avoid any "resale penalties and restrictions" that many developers impose.)
I do not normally recommend that timeshares be included along with the rest of your personal property. I've found it is easier to create a distinct trust or LLC that only contains your timeshare portfolio.
In the future, if you need to transfer ownership quickly for any reason- it can be done with a simple filing to change either the ownership of the LLC or name a new trustee. You may also find that this strategy eliminates the probate requirements upon death that can be more costly than the timeshares themselves..
AGAIN- my recommendation is that you speak with an attorney to ensure any steps you take are done properly.