Hey,
you water too often. Your earth is living too much. The green shouldnt be in your soil.
It looks like it started with 1 cotyledon therefor its getting small leaves, it willl get better with time. You can check my diary, had the same. But my plant overall looked healthier, try not to water her till the pot dries out on top.
You could also transplant her now into less wet soil, the amount of earth she has right now also slow her down in size