A question for all you teens out there ?? im an oldie so please answer?

Daughters mate , not a really close one , went out with her bf , having txt him for two months previous to this , after my daughter dumped him , well this girl was pretty harsh on my daughter , daughter tried to be nice never had a prb with them going out , the x said loads of crappo to the then present gf , so she turned against my daughter.Well now this girl has been dumped and is going out of her way to be nice etc and telling her the bf was cheating on my daughter of which he wasnt. Hope this isnt too confussling for you, would you guys be suspect ?? or has this girl realised and seen the light ??