Hi Anna,
I know you say you are working on the layout but the level of direction you give, especially in brackets, is quite distracting. Also be careful on scene changes - you start off saying it's inside her bedroom but before you've even finished describing the opening scene, she's in the hallway. That's a new scene.
Maybe try writing the whole thing again with just the dialogue then going back and putting the direction in - but just a bare minimum - nothing in brackets. Also if you've said someone is shouting, you don't need to put it in capitals with exclamation marks.
Centre the dialogue (difficult to do on here to be honest) and put the directions on the left.
If the old woman (women? Typo?) is OLD EMMA in the story, use her name, you don't need to surprise the director by "revealing" it's one of the characters later on.
These are all the mistakes I made as well, so I’m just passing on the advice.
Just as an example:
YOUNG ZAC
Why are you crying?
ZAC pulls melted chocolate eggs out of his pocket and offers them to YOUNG EMMA.
YOUNG ZAC (CONT’D)
I have chocolate.
OLD EMMA [V.O]
He knew the way to a woman's heart early on.
YOUNG EMMA eats
YOUNG EMMA
I hate my Easter hat, its ugly.
We can see from the dialogue that “he knew a way to a woman’s heart” refers to him giving her chocolate, because we can see it on the screen while she’s talking. Likewise, if Zac asks her why she's crying, you don't need to tell her to cry.
There are a lot of instances where you need to think about where the scene is happening – if they are in a forest but “duck down behind a mill” that’s a new scene as well.
The layout aside, I like it. I’m not sure how long you intend it to be (movie, one hour drama, series etc) but you reveal quite a lot in these first few lines – depending on the length you may want to flesh out some of the dialogue as it feels like you’ve tried to cram all of the ideas into the opening. Especially the ending - I think there would be more of a conversation before she asks her friend why she didn’t tell her she was dying, this didn’t sound very realistic to me.
All in all it's a great start to introducing the characters and I would be interested in watching/reading more.
P.S. Just to prove a point, I had to edit this to centre the dialogue text!!