Saying goodbye to best friend

On top of everything else going on, my daughter Chloe is not able to say goodbye to her friend.

Chloe has struggled her whole life to make friends. Since September, a new student has been transitioning into the school. These 2 made friends really quickly and after a few months he said he loves Chloe. There is a 5/6 year age difference between them and Chloe explained that she would just like to be friends with, which he accepted. 

Ever since, their friendship has grown, where they would do lessons, activities and spend a lot of time with each other. Chloe would also feel upset without being with him and this is all she wanted to do. She says he is like a brother to her. I cant even begin to exaggerate how loving and caring their friendship is. It was all she would talk about, all day, every day

Unfortunately, due to the boy's situations, he is currently not allowed in school, this has been the past week, and Chloe keeps asking staff when he will be back. It seems like he is not coming back this year but possible after the summer holidays. Obviously she is really upset about this and has been saying "I feel like I've just lost my brother". She is not able to see him, talk to him or anything since he's not in school. 

I hate seeing her upset and want to help but i just dont know how. I've said about writing a letter that she could give staff so they can give it to him and she is thinking about doing this. 

She really misses him and other than the letter, i dont know what to do. If anyone has any ideas, feel free to share them

Lucy