Really good job Meg! You seem to have a very good natural ability to write music. If you continue to understand how music works with chord changes I think it would add even more to it. It is already good, so anything that you learn on that front would only be an improvement. Right now would you have an idea of what kinds of chords you could put in to fit with guitar or piano chords? Take the beginning of various measures and see if you can find spots where you could slightly change the notes to match a certain chord that a guitarist could play. For example, if the beginning of a measure has a D and E, change the E to F# and label the chord as a D chord. You would be amazed at what that will do to overall sound.
Overall an A+ especially knowing that you have limited knowledge of chord structure. Great ear!