There is nothing much wrong with your sentences, but they sound a little awkward. I have corrected them to sound more natural.

Participle II (translation)

1. She looked at his worn-out suit.
2. The young woman seemed frightened.
3. When she was asked, she gave her address.
4. A big decorated Christmas tree occupied the whole corner of the room near the piano.
5. He noticed that she had blushed and looked embarrassed.
6. His voice still sounded dissatisfied.
7. She was a thin woman with a white face and dyed hair.
8. When they ask you, give them my phone number.
9. His uncle had an old friend named Tom who lived in London.
10. She looked at him with frightened eyes and left the room without saying anything.
11. When we asked her, she showed us the shortest way to the station. 
12. His voice sounded disappointed.
13. My mom was one of the four women who sat at the table.
14. They were well known to each other. (good but They knew each other well sounds better)
15. The next day we went to the address given to us by the doctor.
16. When I got to the desk, I found there a sealed envelope there.
17. He could have done more for you, if he had been better informed.

The following sentences simply have to do with the use of commas:

4. A big, decorated Christmas tree occupied the whole corner of the room near the piano. 

10. She looked at him with frightened eyes, and left the room without saying anything.
17. He could have done more for you, if he had been better informed.

Sentence 16 is not wrong, but it would be extremely rare to say, "When come to the desk, I found there a sealed envelope."  Such a sentence sounds, perhaps, old-fashioned.  Stylistically, the use of "come" as a participle sounds odd.  It sounds more natural to use "having" + past participle in this sentence. Moreover, the word "there" would better be placed at the end of the sentence.  It sounds so much better to say, "Having arrived at [come to] the desk, I found a sealed envelope there."