Legal Question in Real Estate Law in Nevada

If your mother is mentally competent (has not been diagnosed with dementia or dependency on psychoactive meds or any other type of impairment of mental capacity), she can give her property to whomever she wishes. That cannot happen with just an oral promise, though.

If she does not have a will or trust, and the deeds continue to show her as the sole owner, there is no legally recognized evidence of the gifts you are suspecting. In that case, her "legal heirs" shall inherit her property upon her death, via a probate proceeding in which a judge reviews the properties, learns of the family relations, reviews any evidence of your mother's intent, and decides whether the Nevada statutes that establish legal heirs apply to the facts of your mother's case. This is a matter for which you should retain a capable probate attorney in the county where the properties are located and/or where your mother resides at the time of her passing.

Unless she is signing deeds to the properties, nothing can happen prior to her death, so your worries may be premature, anyway. You should talk with her and learn what her intentions are before stirring up a pot of soup that may not ever be served!