The Duke of Cambridge shared a touching moment with the little girl during the visit, an act which almost brought her mother to tears.
Prince William drew on his own experiences and opened up about losing his mother while speaking with the young girl, urging her to keep talking about the father she had lost to cancer.
Nine-year-old Aoife looked overwhelmed as the Prince sat down next to her asking, 'Do you know what happened to me?'.
Using common ground to speak to her, Prince William shared some details of what it was like to lose his mother as a teenager.
He said, 'You know I lost my mummy when I was very young too. I was 15 and my brother was 12. So we lost our mummy when we were young as well.'
Drawing on his own experiences, the Duke of Cambridge, 34, was able to give Aoife some advice; largely that talking about your lost one is very important.
'Do you speak about your daddy? It's very important to talk about it, very, very important.'
Aoife's mother, Marie, said of the exchange, 'I couldn't believe it when he started to talk about his mother. It was very emotional and I was willing myself not to start to cry. I almost did.'
And it seems the day was a success, with children and parents taking heed of Prince William's advice, remembering to keep talking about the people they have lost and their feelings.
Marie continued, 'I am telling my children that if they take anything away from this day, it is what he said a out how important it is to talk. Kids do not forget that. Sometimes it hurts but we can remember the happy things too. It is so important to talk.'
The Prince also made a rare comment about his feelings at the time of his mother's death, admitting he was 'very angry'. This year will see the 20th anniversary of Princess Diana's death.
As part of a therapeutic exercise, children and parents were encouraged to make jars filled with different coloured layers of salt, with each salt layer representing a different memory with the person they had lost.
Lorna Ireland, 36, and her son Shinobi Irons, 12, took part in the activity honouring and thinking about their mother and grandmother who had died three years ago.
Speaking about her son's exchange with the prince, Lorna said, 'He told my son that when his mum died he was 15 at the time and he was very angry and found it very difficult to talk about it.
'So it was very important that Shinobi talked to somebody about how he was feeling even now years on. It was very personal and it was very special.'