The step-sister is saying she has power of attorney, but lives in another state and the parent and financial adviser has said the stepsister is not the POA. The parent is now in an assisted living situation since he cannot take care of himself.
If more than one POA exists, the one with the most recent date is the only one in effect. The older POAs are rescinded by the existence of a newer one.
Blood relation, step relation, geographical location are irrelevant. Have everyone show their copies of the POA and whomever has the most recent one has the POA.
If anyone is unwilling to show their POA, assume they don't have one and act accordingly.
SierchioAnswers, Mom2Mom is absolutely correct... POA is an actual legal document. It isn't like calling "it" in tag. A POA needs that piece of paper in order to be POA. If the parent chooses to deem the child POA, have them fill out the appropriate document with a notary. If the step child is POA and the parent is in agreement, the step child must produce the POA document in order for the POA to be in effect. If no POA document is given to the assisted living facility, then the parent is their own agent and make their own decisions.
In Alaska where we lived when my brother was in the hospital I was asked to sign the POA. So, I became the legal power of attorney. However, after he passed his daughter being the only child of my brother was legally declared the POA without paperwork.
POA's do not survive death. You are POA to assist in making decisions in the event the loved one cannot but once they pass away, the POA is no longer in effect. Your brother may have deemed his daughter trustee of his estate but once he passed, there was no longer a POA.
Blood relation, step relation, geographical location are irrelevant. Have everyone show their copies of the POA and whomever has the most recent one has the POA.
If anyone is unwilling to show their POA, assume they don't have one and act accordingly.