These are the lines you are talking about:
Come, gentle night, come, loving, black-browed night,
Give me my Romeo. And when I shall die,
Take him and cut him out in little stars,
And he will make the face of heaven so fine
That all the world will be in love with night
And pay no worship to the garish sun.
The lines tell us that she is in love with Romeo. She wants the night to come quickly because she wants to see him soon (they visit each other only during the night, when no one can see them). We understand that she has fallen in love with Romeo, and the he loves her as well.