*Someone please correct me if I'm wrong, but I believe when you,
( @bigdmicc ), linked your old city to your fb account it was linked "for life". I have heard of mayors creating a new fb account and linking a new city there. You will probably want your new city to be linked to a new/different Google Play or App Store account as well. Another word of advice: You probably won't want to link your city to any child's account, as doing so could disable your ability to buy and sell in global trade and prevent you from joining any club.
I hope you find this information helpful.
Peace
