You should think about investing in a few test kits. This way you can frequently test your water parameters. Water quality should be a main concern when trying to keep fish healthy. You will notice a trend that when someone has a sick fish and asks for advice, the first thing they ask for is the water parameters.
Good luck with Ophelia. Either get some kits or have the lfs
give you the exact numbers and post them here. The adivsors and other knowledgable hobbiest here will probably be able to pinpoint the problem and help you nurse (her?) back to health.