the little one looks to be making a recovery, but if that is your only plant the odds of it being female are not where you want them to be
I would keep it around but start some new seeds. You might want to try out some starter plugs like rapid rooters or coco coir instead this time around. After the plant has a leaf or two start to yellow, you can transplant it into some potting soil that has been flushed out real well. You shouldn't have any big problems using normal filtered tap water or bottled water, but as soon as they start to grow and you see any yellow, they need to be transplanted or they will start to show deficiencies.