Syncing between different Apple ID accounts

My sister runs a photography business, and I have recently decided to do some work with her. We decided to transfer all of her work contacts/pictures/information to a separate "user account" on her PC which is linked with a different Apple ID account. We did this so that I could then create an additional user account on my laptop, and access all of the information linked to that apple ID as well. However, the issue we have now is my sister is often adding new contact info through her phone, and her phone is not linked with the new Apple ID, only the old one. So when she adds new contacts, they do not sync to the new contacts app that I have access to. Is there a way to do this? Or does anyone have any suggestions to better organize this?

Thanks!