She was quite young, not more than eighteen.
( She ( ( ( was ( ( ( quite young ) , ) ( not more ) ) ) ( than eighteen ) ) . ) )
(ROOT (S (NP (PRP She)) (VP (VBD was) (ADJP (ADJP (RB quite) (JJ young)) (, ,) (ADJP (RB not) (JJR more))) (PP (IN than) (NP (NN eighteen)))) (. .)))
She looked older even though she was only barely eighteen. 
( She ( ( ( looked older ) ( even ( though ( she ( ( was only ) ( barely eighteen ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP She)) (VP (VBD looked) (ADJP (JJR older)) (SBAR (RB even) (IN though) (S (NP (PRP she)) (VP (VBD was) (ADVP (RB only)) (ADJP (RB barely) (JJ eighteen)))))) (. .)))