[5] sunt … quibus: Although Sulpicia does not name her concerned friends, we can assume it was obvious to Cerinthus who she meant, probably Messalla.
illa: in apposition with “maxima causa” in the next line, not a reference to the woman who has caught Cerinthus's eye. quibus, dolori: Double dative. The couplet might be paraphrased “Sunt qui timent ne cedam...”.