Six-year-old Bradley died on July 7, 2017 after a battle with terminal neuroblastoma cancer.
The youngster, from Blackhall, inspired families across the North East and beyond with his bravery and care for others.
His cheeky smile and kindness made him friends wherever he went, including then-Sunderland striker Jermain Defoe, whom he called his best pal.
Gemma, wife to Carl and also mum to Kieran, penned a touching tribute to her little boy, who was football mad and supported Sunderland, on social media.
It said: “Four years since I have held you in my arms, since our hearts were shattered into a thousand pieces and our lives changed forever.
"I feel like I have not touched you forever, but I also feel like, how can it be four years, since you left me to become the brightest star in the sky.”
In the aftermath of Bradley’s death, Gemma and her loved ones set up the Bradley Lowery Foundation; a charity dedicated to supporting poorly children with their own fundraising campaigns.
The Foundation supports research into childhood cancers and set up a support line for families of children with cancer across the North East.
Work is also ongoing on a holiday home in Scarborough, named Super Brad’s Pad, enabling these youngsters and their families to make precious memories, as Bradley and his loved ones did.
Gemma, who announced earlier this year that she and husband Carl are expecting a baby girl, continued: “My grief of losing my precious baby has torn me apart and at some points I didn't think I could go on living.
"The heartache is that horrendous, there would be no way to describe it. However, although I still have bad days, I am still here and I am doing what I can to keep Bradley's legacy alive.
“I miss him so so much and there isn't a day goes by I don't think of him and his name isn't mentioned.
“I am super proud of what he achieved in his short six years of life I just hope I am doing him as proud.
"Keep being our guardian angel my little superhero until we meet again.”