Ancestry DNA accounts whose owners have died

[Phoenix]

I went to check cousin's account which I manage, to discover that I can no longer access it.

This probably means that her email address has been cancelled.

Her siblings don't approve of DNA testing, so she never told them. Her email address was based on one of her cats, and her user name nothing like her real name. To provide further security for her siblings, the tree only starts about three generations back.

So... how on earth would anyone gain access to it?

When there was a problem, setting up sib's DNA account, Ancestry would only communicate via his email address.

Even if I provided a death certificate, would Ancestry allow me to take control? Who has ownership of her DNA now?