All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.
The Prophet forbade refusing a gift if there is no valid reason for refusing it. ‘Abdullaah ibn Mas’ood narrated that the Prophet said, “Accept invitations, do not refuse gifts, and do not beat the Muslims.” [Al-Albaani graded it saheeh (sound) in Al-Irwaa']
Ibn Hibbaan said commenting on this hadeeth, “The Prophet rebuked refusing to accept gifts among Muslims in this hadeeth. It is obligatory on a person if he is given a gift to accept it and not refuse it, and then he may reward the giver with a gift in return if he is able to and thank him for it. Indeed, I recommend that Muslims exchange gifts between them because gifts bring about love and remove grudges.”
Also, if you accept the gift, then it is a provision from Allaah even if it comes at the hands of your family or anyone else, as the Prophet said, “If a person receives an act of kindness from his brother without asking for it or aspiring to it, then he should accept it and not refuse it, for it is a provision which Allaah has sent him.” [Ahmad]
Also, Imaam Muslim entitled a Chapter in his Saheeh called 'The permissibility of accepting for the one who is given without asking or aspiring'. The Prophet said, “If I were invited to a meal of a sheep's arm or trotter, I would accept, and if I were given an arm or trotter as a gift, I would accept.” [Al-Bukhari]
For more benefit, please refer to fatwa 317566.
If there is a valid reason that prompts a person to refuse a gift, then he should avoid upsetting the person who offered the gift by clarifying the reason for not accepting his gift. When the Prophet returned the gift of a man and saw the effect of that on the man's face, he said to him, “We only gave it back to you because we are in a state of ihraam.” [Al-Bukhari and Muslim]
An-Nawawi, said in his commentary on Saheeh Muslim about this hadeeth, “This is evidence that it is desirable for a person who refrains from accepting a gift and the like for a valid reason to apologize to the giver and tell him that reason in order to comfort his heart.”
Overlooking the mistakes of relatives and forgiving them and forgetting what happened is good, but if it is their habit to remind you of their favor on you, then you should not accept their gifts in order to avoid that. Ibn Qudaamah said, “A person who has no money is not forced to accept a gift or charity or a bequest or a loan (from others)... as there is a potential harm that others will keep reminding him of their favor upon him because of their gift, charity and bequest.” Accordingly, if you refuse the gift of others for fear of them reminding you of their favor upon you, you are not sinful. Nevertheless, if you accept it from your family and forget what happened so that they would not be upset or offended by your refusal of their gift, then this is more appropriate, especially given that you mentioned that their intention was good. So you should forgive and forget; and whoever forgives and reconciles shall be amply rewarded by Allaah. For more benefit, please refer to fatwa 84351.
Allaah knows best.