We would need to know what is your style? Color and fabric preferences? What will the second bedroom be used for? Pictures of what you already have (and want to keep) would be most helpful, as well as pictures of the flat.

conditions are both shower area and bath tub are required in the bathroom.

Do you have any photos you can share? We do better with both floor plan and pix. I think the 9' area should be devoted to a library/reading nook with bookcases on the two walls and a comfy chair and floor lamp for reading. I see lots of doors but no windows in your space. The stretch of space from the entry to the balcony/gallery should be kept open for traffic flow, so Place the FP on the 7.5' wall to be seen upon entering. I think 'd try a sectional with two equal wings. Put the TV on the 7' wall between the two doors and float the sofa so one wing faces the FP and the other the TV. Use a credenza 25% wider than the TV rather than a TV stand. In the jog that has a 6' and a 4' wall, try a family game or chess table and stools. Be sure to get a big coffee table made of reclaimed wood so people can put their feet up on it.

The dimensions would depend on the age range of the Kid. For child up to 4 years old, the generally table height is 20-22 inches. For children age 5 to 7, a table 22-25 inches high would be a standard size & If your Kid is 8-10 yrs of age height of table would vary from 26 to 29 inches. If still in dilemma, feel free to ask. Thanks!