Did Bella ever found out that the little сердце that Edward gave her was actually a diamond?

Yes, she found out from alice

no, she found out from Jacob, when he noticed the little charm he сказал(-а) "a rock" & that reminded her of what Alice wanted to say before Edward cut her of, she сказал(-а) something about "what's one еще diamond? my point is, he already got one on..." then Bella ended the sentence by adding "you" at the end, so what Alice wanted to say was; "What's one еще diamond? my point, is he alredy got one on ...you" çe ça

yup yup !!

Ты tell me i dont know either i think she found out from alice