Is the questioner considered the daughter of her deceased maternal uncle, based on the saying "the maternal uncle is a father"? Does the deceased know who supplicates for him after his death? And is it permissible to supplicate to Allah to show her what became of her maternal uncle in the grave?

The maternal uncle has a great right and a significant share of dutifulness and respect. However, his kinship is not of the nature of fatherhood to which one may be attributed. Rather, describing him as "father" is an expression of the strength of his kinship and his resemblance to a father in compassion and tenderness. And the saying of the Prophet, peace be upon him: "The maternal aunt is in the position of the mother," means that she is close to her in affection and tenderness. As for supplication, it reaches the deceased by consensus of scholars, and it appears that the deceased is informed of who supplicated for him when he sees the reward of the supplication. Requesting to see the deceased in a dream is not considered seeking knowledge of the unseen, as Al-Bukhari mentioned that Ibn Abbas supplicated to Allah to show him Umar in a dream and he saw him. However, it is better to supplicate for the maternal uncle for mercy and forgiveness and to give charity on his behalf.