By the end of the text, Theo was crying hard, but he immediately shoved the letter away from his teardrop's falling line in order to not ruin the writing that was spilled into it. He no longer cared about his appearance and just wallowed in sadness as he crouched down, the pendulum that was bestowed to him clutched tightly inside his grip.
Theo wailed in sadness, whereas Estelle was caught in a flurry of emotions. Going by the letter and Tertia's timely escape, she should be the fated woman. Not to mention, Tertia did mention the Constellation's Leader, which was one of the identities that she assumed as Estelle Clareste.