Letter to Madoka is a document in Fatal Frame IV: Mask of the Lunar Eclipse.
How are you?
Have you decided on a name for the canary I gave you?
I'm sorry that you're alone all the time, but I'm always thinking about you.
Take the crayons with you, okay?
You like drawing pictures, so I'm sure it will make you happy.
The doctor also said that doing things you like will help with your illness.
So please draw lots of pictures.
I think it must be very frightening to forget so many things, but Madoka, you are a girl of the Tsukimori family, so the moon will always protect you.
That's why there is no need to worry.
Do exactly as Dr. Haibara says and be a good girl.
I'll come check up on you again soon.
Love, your Mother