Lilu took a moment to get acclimated to being in her Animagus form. When she'd changed before, she'd thought she was Sirius, and so the transformation had come with all the history: helping Moony, running with the pack on full moons, using Padfoot as a way to ask for affection when Sirius couldn't as himself. Those feelings were still there, but they were distant and clearly not hers. Now, she was herself. Lilu. Tenderhoof. And she wanted to run.
She took off across the grounds, chasing Padfoot and feeling an unrelenting joy as the cool April breeze flowed through her mane. She felt like she could run forever, over fields and mountains and oceans and the wanderlust she never tried very hard to squash felt even closer to the surface than it normally did.
They ran until they came to Hagrid's hut, and Padfoot paused to inspect something. She came to a stop as well and shook out her mane before concentrating and returning to her human shape.
"That was brilliant!" She said, shaking her hair out in much the same way she had her mane. It was beyond tangled from the run, but she didn't mind. "I wish I could tell everyone."