Claire, at this stage you'd better write in your language as well in order to get the accurate correction.

There is a Chinese teacher named (laowang) on youtube who says Mandarin logic is superb. Mandarin grammar is supposed to follow a principle that says write or speak in the order the words must exist first. Based on Tony's sentence we can see if his sentence produces the correct result... 我的卧室 My bedroom must exist before you can go into the bedroom. 里 (now that the bedroom exist, you can go in 有 have to exist next because it indicates past actions 一朵漂亮的花 a beautiful flower must exist before you can place it somewhere 在桌 the table must exist before you can place the flower on it. 上 on ...self explanatory. I guess Tony's sentence structure checks out.