Prime Account shared issues

[CopperBolt]

I packed in Prime a while ago. Then one day my sister said, “why don’t you join
my family prime and get it free?”
I did that and it worked.
She lives in a different house to me not far away. Anyway.

Now, if ever she orders anything off Amazon I get the orange notification thing on an echo dot at my house. I’ve tried logging in as her account and disabling it but can’t get it to work.

Wondered how if anyone knew how to keep everything separate apart from the prime films bit?

Many thanks. Bit of a long shot I know.