A previously-married woman is more entitled to give a decision about her marriage than her guardian, whereas a virgin's permission is to be sought. Her permission is her silence.' [Muslim]
Original Hadith
عن ابن عباس -ما- أن النبي -صلى الله عليه وسلم- قال: «الثَّيِّب أحقُّ بنفسها مِن وَلِيِّها، والبِكر تُسْتَأمَر، وإذْنُها سُكُوتها».
(مسلم)