A 16-year-old girl, who’s been confined to her room at Seattle Children's Hospital for nearly a month, says she is extremely thankful after receiving a little surprise.

Maga Barzallo Sockemtickem is undergoing post-bone marrow transplant treatment. Her compromised immune system is keeping her in isolation at the moment. But the thing she misses the most while she’s away from home is her cat Merry.

So, the hospital decided to ask Facebook fans to send in pictures of their favorite pets. Three thousand photos later, they began working on the “Cat Immersion" project, where they combined all the cat photos with purring sounds to create a slideshow for the teenage cancer patient.

"I can’t tell you how it feels sometimes, feeling disconnected and cut off from the world, and then with something like cat pictures bringing me back," Sockemtickem said in a blog post. "Thank you. Thank you. Thank you."

Watch Sockemtickem experience the slideshow for the first time in the video player below.

CNN Health