Yes, she manages to steal her clothes.

And so, with her brilliant plan for a prank now set, Hilda then began to make her moves to carry it out without Leonie even noticing

First, after making sure there was no witnesses near, she entered into the Sauna as stealthy as she could, and as she predicted, Leonie was the only one who was inside of the sauna, cleaning itself naked in one of it's chambers.

"Ahhh, this feels great..", said Leonie for herself while relaxing in the sauna with her eyes closed.

With Leonie currently too busy with the sauna to pay attention, Hilda then began phase two of the plan, which was to locate Leonie's bag of clothes, and luckily for her, she left them near the door of the chamber she was using.

"Wow, this is easier than i thought", Hilda thought, and so, in a quick movement, she grabbed Leonie's clothes from the bag without making any sound, and then, she quickly left the sauna, tiptoeing along the way. And with that, ladies and gentlemen, her plan had officially succeded.

"Now all that i have to do is to hide them where she won't find them", she giggled and smirked, for she had just done the best prank ever, and all that she had to do was to hide and see the chaos ensue.

Just as Hilda was finishing her plan, Leonie herself meanwhile, was still just relaxing nude at the Sauna like always, and little she did knew of what had just happened to her clothes. Surely this won't end well for her.