I have general durable POA since 2010 over my mother. She was diagnosed in 2012 with Dementia of the Alzheimer's type. Step sister got new POA in 2014.

You wonder who will win what in court?

If I may be a little pious for a moment, the general idea is that your mother should emerge the winner - with a sustainable care plan operated in your mother's best interests by a trustworthy and competent guardian. Is that what you meant?

We can only go on your account. Your account relates that:

Your mother gave you DPOA in 2010. DPOAs, by and large, relate only to financial and practical matters; but yours may range more widely - what does it say in the document?

Your mother was diagnosed with Alzheimers Disease in 2012.

Your mother gave her husband POA for healthcare in 2014. For her to do this, she must have been mentally competent - able to understand what she was doing. Assuming that was the case - and unless you have different information about her mental status* it's not an unreasonable assumption - there is nothing very questionable about a woman giving her husband the authority to make medical and healthcare decisions on her behalf.

* Note: a diagnosis of Alzheimers does not in itself make a person legally incompetent.

Your stepfather died (when?).

His daughter then applied for temporary guardianship and was awarded it. Were you not notified of the proceedings? Even more curiously, did you not visit your mother when she was widowed and discuss her care with the people around her?

Again unless you say different, stepsister has moved her newly widowed stepmother twice: presumably from the marital home to a facility, and then to a memory care unit or nursing home?

Your chief complaint seems to be that neither the married couple nor your stepsister consulted you about arrangements for your mother's care after she became ill. Six years ago, by the way. What steps did you take to be involved in the plans? What assistance did you offer? Do you have either objections to your stepsister's plans or better proposals to make?

Or is this about recognition of a status you were awarded eight years ago and apparently have done not a thing to fulfil? I am sorry if I am hurtfully misjudging you, but your own account does not mention a single contribution that you have made to either caring for your mother or supporting your step family as her caregivers. Perhaps you've done lots of things for your mother and have lots of ideas for her care but don't like to brag. Have you at least been paying her bills, operating her bank accounts, handling paperwork, visiting her regularly, anything?

To "win" guardianship, you will need to demonstrate to the judge that you will be a better guardian of your mother than your stepsister could be.

At the very least, consider: what will you do if you win?

Were you notified of the guardianship hearing? You should have been. That was the time to object to the assignment. If you were not notified that alone could be grounds for setting the guardianship aside in favor of the DPOA if it covers medical decisions.

If you were notified and did not attend the guardianship may very well remain in place.

Even with her diagnosis documented see if you can go through the medical notes and determine diminished capabilities. Anything that can prove she was not able to make those decisions. Look at her ADL’s, medications, notes, who was with her at Dr appt, continual diminished capacity

You just have to take everything you can showing you had POA and documentation showing her diagnosis. Step-sister will have to produce her POA and then u can say Mom could not assign POA because she was not competent. I would also bring up the fact that ur a blood relative, as step-sister is not. This may help. You never know how a judge will rule.