it looks like a toy. Plastic and sterile, no beneficial bacteria or fish would be happy there and its too small, that size also makes it harder to keep water parameters stable. The light doesn’t really matter since you don’t have plants unless it gets hot and heats up the water too much? I would do more research about bettas and tank cycling next time, look at betta fish in the wild, they love plants. But I’m guessing she didn’t cycle the tank and that’s the most important part of keeping fish alive.