With her initial mistake ironed out, Sinead's Summoning Charm seemed to go without incident; the snowball zoomed neatly towards her, not even directed at her face but instead at her chest so she actually managed to catch it. A small miracle in itself.
Achieving accio was only half the battle, though; and depulso had the added catch that aim was necessary. Well, this could be interesting... but she'd never get anywhere if she didn't at least try. She carefully held the snowball on a flattened palm at arm's length and intoned the spell with all the gravity she could muster, willing it to land back in the chest.

Her aim was off- the ball wasn't on the other side of the room or anything, but it was clearly about to land about a metre short of the chest. Her face creased in frustration and she fisted her hands in a sudden spike of annoyance- why couldn't it just go right? Wasn't casting in the first place meant to be the easy part?
As she moved, though, her wand seemed to jump in her hand, unbidden by her, and the ball executed a bizarre sideways hop through the air to fall neatly onto the top of the pile.

Oops. Unintentional magic was embarrassing; that was what emotional, untrained kids did when they didn't get their way. But equally, she had accomplished the task at hand, so she wasn't exactly sure whether that made it a good thing overall or not...?

Whatever the case, she wasn't going to improve any further without additional practice, so she flexed her grip on her wand a few times and cast once more, determined to perfect her aim as well.