After a minor brain injury, a cynical young woman learns she recently made the decision to come forward about a crime from her past; but, unsure if she is up to the task, she must work to find out who she spent the last two years becoming and whether the shoe still fits.

So would it be safe to assume she's lost her memory and doesn't know what happened in the last 2 years? Does she return to the home she once had to find she's evicted. Does she call family and realise she's not talking to any of them?

I started thinking Suddenly 30 - she"grows up" overnight to realise she got everything she thought she wanted but found out she was a terrible person and had hurt everyone she cared about.

but good point above - is it to remember what happened over the last 2 years, to change who she had become? to solve another puzzle?

The logline starts well: "After a minor brain injury"

A young woman: I would then replace young with an adjective that describes her character.

However, this is where the logline starts becoming vague: Works to find out who she spent the last two years becoming... not sure how this looks on screen. Does the woman go around to all her friends asking questions? Does she read her diary?

Also, I am not sure what her ultimate goal is.

Is her goal to regain her memory?

Is the goal just to discover who she is?

Or is it about overcoming challenges, because if that is the case you should say what is the main challenge?

In other words, if her goal is to overcome challenges you should be specific. (Because I have no idea what challenges she must overcome, I have? no idea what the stakes are, nor do I have any idea what the main conflict of the story is)

For instance: her goal might be, to make amends to her family for the way her former self treated them. (As an example) and now the reader would know what is the challenge she faces.