How would you say "She said goodbye too many times before." in Latin?

Cicero provides a possibility for "too many times" with nimium saepe:

Quare "bene et praeclare" quamvis nobis saepe dicatur; "belle et festive" nimium saepe nolo (Cicero, De Oratore 3.101.2)

I think the meaning is even clearer with Seneca's Medea:

Quodsi nimium saepe vocari quereris votis, ignosce, precor:
But if you protest at too frequent a summons from my entreaties, forgive me, I pray:

Cicero uses nimium joined with saepe often, perhaps too often, since it's rarely found in other others (once in Seneca, the above passage, and I think twice in Ovid, but I haven't translated the passages in full to see if they belong together or if nimium goes with another word).

You could also easily just use the comparative or superlative forms of saepe, which would get the point across. In searching the Loeb library, I found several translators who have done that, so it's not just my intuition.

While Draconis is right that you don't need to translate "she", you might consider it if you want to single the subject out. For this, you could use illa, "that woman." For this particular sense of illa, see Lewis & Short:

C. Opp. to hic, to indicate that object which is the more remote, either as regards the position of the word denoting it, or as it is conceived of by the writer; v. hic, I. D.—

So saying illa valedixit would have the same sense as the English "that woman."

I really only bring this up because the previous line has (and the song is called) "this love," so it provides a nice contrast: hic amor, illa mulier.