My Parent Doesn't Have a Designated Power of Attorney. Which Child Should Be the POA?
If your mother/father is competent, she/he must choose an agent under her/his durable power of attorney. If she/he is not, you would have to go to court to have one or more of you appointed guardian.
If you can’t agree on who that would be, an attorney specializing in Elder Law can help.
Otherwise, a judge will have to decide. Unfortunately, any dispute in court can be time-consuming and expensive.