"An awkward silence built a wall between them."It made the relationship between them further apart.This was all because of the awkward silence between the two of them. This is what the quote means.
"And his smile answered her telling her he knew she had felt it."It means he could tell that she could feel it because of her smile . He smiled back because she would tell he knew. This is the meaning of the quote.
"Mamma my finger and angry thorn stabbed me."It means that the thorn was very sharp and deadly. It scraped her finger.This is the meaning of the quote.