Here are some points to consider.
Are the characters complete?
Look at the names you've chosen. I've written rough drafts with a character having one name and then in the re-writes changing the name to make it stronger or even more descriptive of the person. Think about a character named Rafe. sounds strong but what if he's really a Larry or a Tom in the flesh or by his ability. Sometimes a name comes before the character and I know this is right. In one book my hero was called Ari and the heroine Ria. Those names came at the tip of my pen and I couldn't change them.
How do they speak?
Speaking is part of us. I love to just listen to other people speak and catch the rhythm of their words. Each character should have an unique voice that's partof who and what they are. The language they choose often points to their education or their profession. If you've ever listened on a bunch of nurses gathered around a table. The things they often talk about wouldn't be your choice of topics. So when you'rewriting dialogue, be sure to listen to what the people say and how they say. Facial expressions and body language often point to what they're saying isn't what they're thinking or feeling.
What do they want and what do they fear?
This is more to add to your story. What they want can become a goal but it also can be something small like a smile or a thank you. What do they fear. Not necessarily the big things. Maybe then are afraid of spiders, mice, snakes or some other thing. We're talking about the samll every day fears, not the fear that drives them to success. I have a heroine who is afraid to speak to someone in particular when saying something would solve a lot of problems.
How does the character react when they're in a challenging situation>
This will form a lot of the story. Without conflict there could be no story. even of the characteris afraid, this could be a great vehicle to developing the character.