Was she allowed to do this?

Zhenya was trying not to giggle when she walked into the Wizarding Suite. She was wearing her weekend clothes, which were comfortable and daggy, the perfect study clothes.

Yes. The barre. It was going to be green. Zhenya couldn't stop herself from doing a bit of ballet at the barre. She just loved to dance, but after a few minutes, it was time to get on with Charms. She only had a few more minutes until her allocated time was up.

She pulled her wand out, pointed it at the barre, pictured it green, and said "Colovaria." Delighted that it worked, Zhenya saw the barre turn green. Zhenya grabbed hold of it, did a series of plies, then left the Wizarding Suite and its pretty new green barre.