Day 2: using the prompt "Coming of Age"-genre. Apparently, since it's a genre, it can't be just about the celebration of becoming an adult. It is more about personality change and becoming more mature. That's how I understood it at least.
End of Childhood
Since the hasty departure from Valinor, Itarillë's life had changed quite a lot. Her family had left for a new world, been sent into exile, been on the run since that day when she saw her father and her uncles and their fathers stand upon the barricades, debating heatedly as for how to proceed. When they had left fair Tirion the faced another obstacle. Their passing was hindered, and it was all unclear as for who drew his sword the first, but the Noldor left the haven with victory and stained blades. And people said that Itarillë must be very brave for going through it all so stoically despite her young age.
But she wasn't afraid: she really had no reason to. Whenever she was worried, her father would take her hands into his own and tell her everything was all right. Whenever she couldn't sleep because of her thoughts running back to Alqualondë, her mother would kiss her forehead and sing her a lullaby. She was certainly old enough not to need lullabies, but she always felt comforted when her dear mother sang her a familiar tune.
On the journey north people still admired how valiant she was. Her uncle Findekáno would often ask how she felt today, auntie Irissë would chat with her, Ingoldo would offer his warmer cloak for her to borrow if she looked cold. But she would smile endearingly and tell them she was fine. After they were deprived of their ships, she was forced to walk longer distances than she had ever walked before. She saw her uncles less often as they and his father would usually walk in the lead with grandfather Nolofinwë and Irissë would walk sadly beside Findekáno, neither of them talking. So Itarillë went always with her mother. And still she wouldn't worry too much. She was admired for her optimism and her mother would hat her head as if she still was a child.
But the day Itarillë saw her mother lose her balance and cling onto a brick of ice, the day she saw her sink into the dark water... that was the day she was no longer a child. Her father would still take her hand, her uncle still sing her a song, and her aunt still strike her hair. But she would turn away. She was still young, but the child she had once been was no more.