"We drove past and my children felt sad and asked if we could buy him something to eat.''
The family returned with a hot plate of chop suey and potatoes, as well as a bag of fresh fruit including an apple, nectarines and a banana.
"My children were [rapt] and couldn't wait to give this homeless man some food,'' she said.
Pulling up to the kerb, her young son delivered the meal into the man's hands.
The woman said her kids felt good about what they had just done and said: "Hope he enjoys that.''
As they drove away, the children thought the man may like a drink. The family stopped to get him a drink before heading back to High St.
"But as we got closer, we noticed food over the footpath and on the road,'' the heartbroken mother said.
Photos show the man sitting on the footpath still, but with the plate of food and fruit scattered on the road in front of him.
"My children were gutted...I couldn't believe it. I looked at my children's faces and I couldn't utter a word. I was speechless.''
The woman said although her children were left disappointed, she told them: "Not all are like that.''
The post - which has been shared by many on Facebook - has attracted a huge amount of support for the family.