From LLPSI *Fabullae Latinae*, the 67th story, "Infans Repertus":

> Dum haec sēcum cōgitat, subitō mulier in viam exit multīs cum lacrimīs clāmāns: “Nūlla fēmina mē miserior vīvit! Melius erat mē mortuam esse quam sine īnfante meō vīvere!” 

For context: Syra has just found an infant abandoned in the middle of the road and is considering bringing the infant to a nursemaid. The story uses the present tense throughout it. 

Is there a reason why the woman uses "erat" instead of "est" in the last sentence? I saw from this helpful post - [Change of tense from present to imperfect][1] - that it is quite common in Latin to switch tenses. However, I'm not quite sure what nuances the tense-switching here induces.

Thanks in advance!

  [1]: https://latin.stackexchange.com/questions/21835/change-of-tense-from-present-to-imperfect