I guess on google play you should be able to change from one to another,about gmail and chrome,I am not sure.Logout from the one you are on and login to the other.
But that's the issue, we don't want to use it simultaneously. I don't want to see her notifications. It's there a way to use the phone separately, so we only see our own gmail, chrome bookmarks etc?
In the Z2, you would be able to configure only one gmail address for the gmail app. So should that solve your problem? Cant still exactly get what you want to do.
We want to switch between google accounts.. So each person only sees their gmail, their chrome bookmarks, their settings etc.. a bit like 2 people having different accounts on a pc....