Also I dont see a filter. And yes plastic blocks UVB rays, and to me it doesnt look like it's in direct sunlight (not that you should put it in direct sunlight!) but if thats the case then they arent getting any UVB and the basking temperature is probably not correct.
If your parents have such a problem with the turtles inside then you should purchase a large stock tank (100 gallons or more) and buy a pond filter, set it in your yard, and you'd be all set.



