Reference: Fataawa al-Lajnah ad-Daa.imah lil-Buhooth al-‘Ilmiyyah wal-Iftaa. – Volume 18, Page 30, Fatwa No.4921, Question 5
Question: Is it permissible for a young woman to abstain from getting married [again] after the death of her husband?
Response: The Sharee’ah strongly encourages marriage, so it is upon the guardian of this young woman to advise her to get married and encourage her in this. However, if she refuses [to do so] and does not fear any fitnah for herself, then she can abstain from marriage and that is her affair.
And with Allaah lies all success and may Allaah send prayers and salutations upon our Prophet (sal-Allaahu ‘alayhi wa sallam) and his family and his companions.