"Cross" goes well with "belonging to God," since the cross is one of the primary symbols of Christianity and Catholicism.
Dominique's symbol is "Ji" ("itsuku") which means "love, treat with affection." It's 13 strokes, and phrases formed with it include "jizen" (charity), "jihi" (mercy, benevolence, pity), and "jiai" (affection, kindness, love). The official English definition of Dominique's kanji is "love."
The significance of "Ji" is pretty obvious with regards to Dominique- she is a very loving and affectionate person, and in turn, everyone feels affection for her.