Your models give crisp and sharp objects in the 3D preview.
When I render an image in high quality, the result is also excellent.
I can't see any jagged lines.
However, the images for the textures have been badly chosen. The wood textures are far too big (2487x1500 pixels) and may cause problems. I propose you reduce these images to approx. 512x512 pixels. On the other hand, some of the other images are too small, e.g. the blanket on the left bed.
I hope this answers your question.
Hans
