When I go to https://discussions.apple.com/ and logon, it takes me to https://idmsa.apple.com/, and LastPass fills in my wife's ID. I have to drop down to my ID. How do I control which ID & password? I have all of our LastPass stuff in a shared folder.
You can set the entry for your wife to not autofill. Then only your entry will autofill.
Because you share these, it might be best to set both to not autofill.
As for custom ordering, I dont believe that functionality exists.