Recently I was encouraged by Revelation 5:8a which reads, “there is a golden bowl in heaven full of incense, which are the prayers of the saints.” We can get weary in praying over a situation if we do not see anything happening.
My husband and I experienced this in prayers for a family member which took 15-20 years to see what we prayed for answered in her life. I think the secret is to stop asking and start praising that the Lord has heard and is undertaking your petition. I know He was doing a work in us during this time that seemed interminable. In addition there is a perfect time when the person being prayed for can receive the answer. I encourage you to know that the petition you prayed for is in that golden bowl at the throne room. The answer will come in the right time.