Can my sister be a financial POA for my parents and I be a medical POA for their heath care?

I take my parents to medical appointments, fill prescriptions and can ask generic questions to health care providers. But when it comes to discussion's about other medical issues I'm told I need to be a power of attorney to have access to this information. My older sister is the poa for my parents financial needs. I don't feel the need to be involved in financial issues since my sister does a good job and keeps the family up to date on her decisions. I have a back ground in elder care and we agree that medical issues should be in my care. Is it possible to have a poa for each?
Thank you