I am trying to get a POA for my mother, she has lived in Texas for many years and recently (within a month) has been moved to California to live with my sister. I sent my sister a Texas POA to do before the move and it wasn't done. Now that my mother is living in California, do I do one for California instead even though her ID is still Texas?
You don't clearly understand POA.
POA is not something you GET over someone. It is something that THEY confer upon you, and they have nothing to do with any state whatsoever. They are a legal document in which a competent person appoints someone as POA to act for them when and if they are unable to make their own choices. That person will act in the manner their believe the appointing person would wish, or in their best interests. Every single record is to be accounted for and there are particular ways of putting yourself on accounts in order to sign as POA. You are responsible for every penny in and out of accounts if you are managing finances.
Now you may be speaking of a MPOA or medical power of attorney which is little more than an advance directive appointing someone as Medical Power of Attorney for medical decisions if someone is able to make their own decisions. These will generally go state to state as well.
Look up/google POA for your state and look at the rules and options or see an elder law attorney with you questions, and do realize, again, this is not something you GET, but something that is GIVEN and only by a competent person.