Say Ayako had a diary that she wrote during her time at Haibara Hospital. It would be something like this. o3o (I tried researching everything that happened in the game to make this more believable, but I have missed some facts, so forgive me.)

Entry 1:

It's my second day in this hospital. That nurse told me that writing journal entries would be helpful with my illness. Let's see how that catches on...
Anyhow, that guy visited me today. He showed me a secret room in the corner of my room. That's pretty cool. I'm sure that I knew him before I was sick. He's fairly nice.
Also, that nurse gave me some dolls to play with. She said that they could help with my illness too. I'm already bored of them.

Entry 2:
That nurse is bugging me. Only five days in, and I hate it here. That guy's visits are nice every now and then, but I still get lonely.
I really love my back room. I decorated the bed with strings. I still have leftover string, which surprises me. My first room has this cool lamp that puts pictures on the wall.
Other than that, nothing much is going on.

Entry 3:
I'm already done with my dolls. I used my leftover string to hang the arms and legs from the ceiling. I don't know what to do with the heads or chests, so I left them on my bed.
That guy didn't visit today. Oh well.
Stupid nurse is still bothering me. I'll show her. I did enjoy the look on her face when she saw my artwork hanging around in my room.

Entry 4:
I heard that doctor say that I had "exesif behaivor". I may be a kid, but I still have ears. I'm still here! I'm - what's the word? - frustraited!

Entry 5:
I found a new toy today. It lives in room 203. I told it to come over to my room today, but it hasn't shown up yet. Maybe I can toy with it by cutting a few of its hair off. Maybe a bit of its cheek...

Entry 6:
The guy visited me again today. He said it might be awhile before he sees me again. I wonder if he was in trouble. It's okay though. I have a new toy to keep myself preoccupied with.
That nosy nurse wanted to look through these notes. She never said it, but I could tell by the way that she looked at my papers.
Also, that kid in the room next to me stole my lamp. I hate leaving my room, so I told that pathetic nurse to bring it back.

Entry 7:
Haha! How pretty! I pushed my new toy down the stairs. You know, those giant stairs in front of the main doors. Bruises began to grow on its pale skin. It cried fearcely. So pretty! It was hurt, but I've yet to break it.

Entry 8:
I haven't slept all night. I walked around my room, following the pictures the lamp made on the wall.
My doll stays in its room a lot, but today was different. It laughed and sounded happy. I soon realized that it replaced me with a stupid red bird. How dare you!

Entry 9:
Yes! I found it! The prettiest thing ever! That boy's stolen items are absolutely nothing compared to this.
Yes, the bird's blood is redder than its feathers. Its pathetic chirps have now ceased. I'm sure my doll would like to keep it now.
Stupid nurse scolded me, but who cares? Maybe she would like to become one of my arts. I'll only give her a sample. She don't deserve to be pretty.

Entry 10:
My doll is gone.

Entry 11:
After a whole month, the guy finally came to visit me. He was smiling and having fun. He hid me in the deepest part of my room, telling me to hide until he came to visit me again. I did so, and I'm still waiting.
I've never been so bored in my life!

Entry 12:
The guy came back! He told me it was safe to come out now. He seemed a little sad. He told me someone close was asleep, and he was worried for her. Who is she? Was I replaced again?
I begged him not to leave.
He did.

Entry 13:
I finally gave that nurse what she deserved.
What a lovely face she has now!
But I'm done with her. I'm bored again.

Entry 14:
The nurse came by less and less.

Entry 15:
I was told it was my thirteenth birthay. Who cares? No one will celebrate it.

Entry 16:
It's been seven months. The guy finally returned. I was surprised though. He held me in his arms, telling me that he missed me. I had never been so confused in my life.
What was I to him?
If I was important, then why couldn't I leave with him?
I asked him to have the nurse attend to me before he left.

Entry 17:
It's a new year.

Entry 18:
The guy visited. He gave me a picture of a woman, the one that was asleep. She kind of looked like me, only with wavy hair.
He said that he had to go hide now. If I had enough time, I could have told him to hide in my secret room.
I wonder if he knew it was my birthday today.

Entry 19:
that mans face is weird
i cant focus im scared
SOMEBODY HELP ME

Entry 20:


(A long streak goes off the paper.)

Explanations
Mispells- Ayako's a kid. Of course mistakes like that are made. o3o

"The guy"- This is You Haibara. He would visit Ayako in the hospital.

Entry 4- Shigeto Haibara compared You and Ayako as having excessive behavior.

Entry 6- This was when You left to work at his clinic in Tokyo.

Entry 10- This was when You kidnapped the five girls, including Madoka.

Entry 11- At this time, You is playing his "game of chase" with Choushiro. Not wanting Ayako to be involved, he hid her in the back room until the coast was clear.

Entry 16- I love father-daughter moments. ;n;

Entry 18- He has to "hide" because he's continuing his game with Choushiro.

Entry 19- On the Day Without Suffering is when she saw a Blooming man outside. She hid in her back room, waiting for help. (Also, I intended to have this happen on entry 19, since nine is a cursed number in Japan.)

Entry 20- Since she's slowly going mad, she has nothing better to do but constantly write in her diary until the Blooming takes her.