You have not provided enough information. If your parents are incapacitated, then you can report this to APS. You could also petition to become guardians/conservators. You do not have a legal right to an "early inheritance," however, or any inheritance at all, for that matter. So it is possible that you may not be able to achieve your objectives.
***Please be sure to mark if you find the answer "helpful" or a "best" answer. Thank you! I hope this helps. ***************************************** LEGAL DISCLAIMER I am licensed to practice law in the State of Michigan and have offices in Wayne and Ingham Counties. My practice is focused in the areas of estate planning and probate administration. I am ethically required to state that the above answer does not create an attorney/client relationship. These responses should be considered general legal education and are intended to provide general information about the question asked. Frequently, the question does not include important facts that, if known, could significantly change the answer. Information provided on this site should not be used as a substitute for competent legal advice from a licensed attorney that practices in your state. The law changes frequently and varies from state to state. If I refer to your state's laws, you should not rely on what I say; I just did a quick Internet search and found something that looked relevant that I hoped you would find helpful. You should verify and confirm any information provided with an attorney licensed in your state. I hope you our answer helpful!
This situation is not clearly explained. If you have an issue in S. Jersey I am a licensed attorney in New Jersey with an office in Turnersville.
This is not legal advice nor intended to create an attorney-client relationship. The information provided here is informational in nature only. This attorney may not be licensed in the jurisdiction which you have a question about so the answer could be only general in nature. Visit Steve Zelinger's website: http://www.stevenzelinger.com/
Although your question isn't very clear regarding what you refer to as a "monthly early inheritance,", if you think that your parents are being exploited or abused, you should contact Adult Protective Services.