Lily Luna Potter was seven-and-a-half years old, thank you very much. She needed no help learning how to fly a broom, so James could very well sod off.
James chuckled to himself as he watched his little sister run back to the Burrow with scraped knees and tears in her eyes after her third fall. After all, James was about to set off for his first year at Hogwarts. He was much older and wiser when it came to such things as learning how to fly a broom. He walked back into the overcrowded kitchen of the Burrow with his head held high, confident that Lily would return to him begging for help.
Lily raced straight towards the upstairs bathroom, but just as she reached the door, she tumbled headfirst into Lorcan Scamander, causing her to fall onto her bottom and erupt into tears and sniffles.
Lorcan had just been leaving a game of exploding snap in Albus and Hugo's temporary room as he was nearly knocked over by a flurry of red. As soon as he realized it was Lily who had fallen, he grabbed a wad of toilet paper from the bathroom and began to help her clean up her tears and knees.
Lily woefully told Lorcan the tale of her cruel older brother treating her like a child, and expressed her disappointment that she was, indeed, in need of help.
Lorcan told Lily the story of how he had learned how to fly the summer prior, when he was seven-and-three-quarters, and he had fallen off at least fifty times. There was a devious glint in his eye as he suggested that he teach Lily how to fly behind James' back, so that James would be dumbfounded at her new ability.
This suggestion immediately quenched Lily's tears, and two weeks later, she was able to watch James' mouth drop open with surprise as his little sister flew by him, faster than even Albus could go.
Lily shared a private smile with Lorcan at the lunch table the next day. This was the first of many adventures between the two, which only got more rambunctious and risky when Lily joined Lorcan in the house of Hufflepuff a few years later.