She vowed to memorize Soorat Yoosuf and she did memorize it, but now she has forgotten some of the verses
Question

                I vowed to memorize Surat Yusuf when I graduate from university. A while after graduation I memorized it, but there are few verses I forget. Is my vow considered fulfilled once I completed memorization, or it is not yet fulfilled?.
Praise be to Allah.The one who vows to 
    memorize a soorah of the Qur’aan and does memorize it, has fulfilled his 
    vow, even if he makes a mistake or forgets some parts of it after that. 
    These mistakes and forgetting happen to most of those who memorize Qur’aan, 
    but they can be corrected by means of regularly reviewing what one has 
    memorized. 
We advise you to keep 
    refreshing your knowledge of the Qur’aan, and review it regularly. The 
    Prophet  (peace and blessings of Allaah be upon him) said: “Keep 
    refreshing your knowledge of the Qur’aan, for by the One in Whose hand is 
    the soul of Muhammad, it is more inclined to escape than a camel from its 
    rope.” Narrated by al-Bukhaari (5033) and Muslim (791), who said. 
What is meant is that if 
    the Qur’aan is not reviewed regularly, it will escape from you, as the camel 
    escapes from its rope with which it is tied. 
We ask Allaah to help and 
    guide us and you. 
And Allaah knows best.