In April 2013, it was made public that Vallejo was expecting her first child with Julio Sarmiento, one of the heads of the Communist Youth of Chile and her partner since September 2011.
Pada bulan April 2013 dipublikasikan bahwa Vallejo mengharapkan anak pertamanya dengan Julio Sarmiento, salah satu kepala Pemuda Komunis Chili dan pasangannya sejak September 2011.