CHATGPT: Certainly, here's an example of a case where an adult only child prevailed in an undue influence case where the parent was still living:
In the case of Gravley v. Gravley, 185 S.W.3d 657 (Tex. App. 2006), the decedent was an elderly woman who was still alive at the time of the lawsuit. The decedent had one adult child, a daughter, who filed a lawsuit against the decedent's brother and his wife, alleging that they had exerted undue influence over the decedent.
The trial court found that there was sufficient evidence of undue influence and entered a judgment in favor of the daughter. The court held that the decedent's brother and his wife had taken advantage of the decedent's weakened physical and mental state to gain control of her affairs and influence her decisions.
The brother and his wife appealed the trial court's decision, but the Texas Court of Appeals affirmed the trial court's ruling. The court noted that the daughter had presented evidence of the brother and his wife's undue influence, including evidence that they had isolated the decedent from her friends and family, controlled her access to medical care, and made decisions about her finances without her input.
It's important to note that each case involving undue influence is fact-specific and will depend on the specific evidence presented. Therefore, the outcome of one case may not necessarily be applicable to another case. Additionally, the laws and legal precedents related to undue influence can vary from state to state.