My youthful Alpha stepbrother

Following the tragic deaths of Marilyn's mother and stepfather, she received an astonishing revelation that she had a younger half-brother named Lynn, residing hundreds of kilometers away within a different wolf pack. Despite being eighteen years old, Lynn had not yet undergone his first transformation into a wolf.
With the unfortunate demise of Lynn's grandparents, Marilyn, unrelated by blood, found herself appointed as his sole legal guardian, bearing the responsibility to care for his well-being.
The harsh realities of their impoverished existence had molded Lynn into a reticent and introspective individual. However, akin to the unwavering resilience of a young poplar tree, he grew into a poised and striking young man, fearlessly confronting life's challenges.
On the night when Marilyn brought him to her home, Lynn, who had shown no prior signs of undergoing the wolf shift, unexpectedly entered his awakening phase. Restless and uneasy, he stood in the living room, beads of sweat forming on his brow as he gazed at Marilyn, softly murmuring, "Sis……, I believe I may be running a fever."
This is a story about a little puppy transforming into a big wolf……