𝐡𝐞𝐚𝐝𝐜𝐚𝐧𝐨𝐧 — 𝐩𝐞𝐫𝐦𝐚𝐧𝐞𝐧𝐭 𝐫𝐞𝐬𝐢𝐝𝐞𝐧𝐜𝐞 .
As Secretary General of the Ministry of Tourism and Antiquities, it is Isis' job to assist in the restoration and preservation of Egyptian artefacts, as well as oversee all of Egypt's archaeological museums, secure the return of stolen or lost artefacts, implement strategies to reduce theft and destruction of artefacts, and boost tourism through the education of Egyptian history and culture.
The wide scope of her duties means that Isis has a demanding schedule that often requires her to travel abroad to meet with various leaders, archaeologists, and professors to ensure that any Egyptian artefacts in their museums are taken care of appropriately, or returned to their rightful place in Egypt if not.
All of that to say, Isis has lived in several different locations since the end of the series. Following Atem's return to the afterlife, Isis was tasked with overseeing the safe transfer and return of some artefacts from the British Museum in London, which required her to live there temporarily for a year.
By the time the events of DSOD pass, Isis is once again transferred; this time to Berlin. Her current job is as the Museum Curator for the Ägyptisches Museum und Papyrussammlung ( Egyptian Museum and Papyrus Collection ) and Berlin currently acts as her permanent residence; though, again, she is often required to travel abroad for events and various tasks related to her occupation.
It is worth noting that, although not fluent by any means, Isis has a conversational understanding of German and can communicate easily enough with her German colleagues with minimal assistance from a translator.