SOLVED. Y/A Holocaust fiction novel, daughter of a commandant falls in love with man inside and writes letters to him. [s]

[Holly]

The girl decides to rescue the letters from being burned knce she realises they are never getting sent and takes them home to read and send. She starts replying to one mans letters pretending to be his wife who lives in another camp and eventually falls in love with him. She brings in supplies like food and socks to the man until I think they are caught out.
Read in 2019ish.

[Kris]

Holly, how old are the main characters? Is this book for adults or teens?

[Fiona]

The Love That I Have, by James Moloney:
Description on Goodreads:

Margot Baumann has left school to take up her sister's job in the mailroom of a large prison. But this is Germany in 1944, and the prison is Sachsenhausen concentration camp near Berlin.

Margot is shielded from the camp's brutality as she has no contact with prisoners. But she does handle their mail and, when given a cigarette lighter and told to burn the letters, she is horrified by the callous act she must carry out with her own hands. This is especially painful since her brother was taken prisoner at Stalingrad and her family have had no letters from him. So Margot steals a few letters, intending to send them in secret, only to find herself drawn to their heart-rending words of hope, of despair, and of love.

This is how Margot comes to know Dieter Kleinschmidt - through the beauty and the passion of his letters to his girlfriend.

And since his girlfriend is also named Margot, it is like reading love letters written for her.

[Rainbowheart]

The Love That I Have for Fiona's suggestion.

[Holly]

Yes thats it! Thankyou everyone :)