First I have never heard of this and I would do as Anuksha suggested before getting to worried:
She probably had crazy drink at that bar, and those traits will be back to what they used to be after couple of hours.
If the traits do not turn back to normal you can follow this to get them back.
Ctrl+Shift+C (Cheat Console Opens)
testingcheatsenabled true (Enter)
Shift+Click your Sim
Select - 'Change Active Sims Traits'
The Trait options window will pop up and you can change the Sims traits around then click the tick and your Sim will have their traits back.
Ctrl+Shift+C
testingcheatsenabled false
(I recommend turning testingcheats off if you are not going to use it all the time, as some of the options that come from it could mess up things)
Welcome to the Forum as well!