Disclaimer: I own nothing of Harry Potter, all hail JK Rowling!
Over the next few years, Sabrina watched with an aching heart and continually simmering anger from her inner Veela as Harry was practically made a slave to his 'loving family'. The healthy, happy baby she'd rocked to sleep in her arms at the Potters' family manor quickly became a starved, ill-dressed, quiet, submissive boy while his cousin was a selfish, loud, spoiled whale of a brat.
Since Harry was rarely let out of his cupboard, let alone the house, Sabrina had little opportunity to look upon him and what she did see alarmed her greatly. So much so that she began sending letter after letter to Albus and Minerva, begging them to do something. Albus chided her for over-reacting to what was surely only discipline. After all, blood was everything in the Wizarding World; why should Muggles feel different? Minerva only said that Albus knew best and that Sabrina should just let things be.
This naive behavior regarding Harry's home life was astounding. Sabrina had to exert great control over her Veela blood to keep from storming the house and hexing the Dursleys to within an inch of their miserable lives before taking Harry away and then cursing those responsible for putting him there with something horrid. She knew that if she did either thing, she'd probably go to Azkaban and Harry would just be sent back to his bad situation. So she began planning how to be able to interact with Harry under the radar while still adhering to Albus' ruling.
When Harry was three, the Dursleys went on their first vacation, leaving the boy with 'that crazy cat-lady' Mrs. Arabella Figg. Since Sabrina was familiar with the woman, she took advantage and visited whenever Harry stayed over. She put a glamour on at those times, appearing to be a tender-hearted vet who assisted Mrs. Figg with her cats. She always made sure that Harry was well fed at these times, trying to make up for when he went without food, which was much too often.
It was agony for Sabrina to watch her god-son go through such horrible things when everyone else in the wizarding world assumed that the Boy-Who-Lived was spoiled rotten by fawning relatives just like any other pureblood child would be with his fame. As if, she fumed silently. They probably wouldn't even believe the truth if she had the evidence on the Daily Prophet's front page!
The final straw came a month before Harry's tenth birthday. The day, Saturday, was extra hot and sunny without wind and Vernon had taken advantage of it. He'd ordered Harry outside, locking the door behind the boy while the others went shopping for Dudley and then to a movie. 'The freak' was to clip the hedges, weed and water the garden, paint the fence... the list was impossibly long and no food was to be provided. If the boy wasn't finished by the time they came back, Vernon had threatened to withhold food for a week and lock Harry in his cupboard yet again!
Sabrina, who had been listening at the window, watched as Harry worked as fast as possible, trying to beat the rising sun. He was doing well but he'd been without food for two days already and soon became lethargic. Sabrina nearly had a heart attack as the boy used the huge, heavy shears to clip the hedge around the back of the house; she was so afraid that his fatigue would prove fatal.
Despite Harry's best efforts, he'd barely completed half of his chores before the Dursleys came home early. Not caring that Harry was nearly delirious from the intense heat and lack of water, Vernon literally dragged the half-conscious lad inside, snarling and giving him a vicious kick in the ribs. As the door closed, Sabrina heard the sound of a very hard slap and her inner Veela shrieked. Overcome with maternal rage and fear, Sabrina stormed to Arabella's house and asked to use the Floo. She wasn't going to just sit and watch anymore, something had to be done to help her god-son and no-one was going to stop her this time!