【答案解析】The different values of the two sentences above are worked out by the conversational implicature. For example, in the first sentence, "already" is used, which implies that something should be done; and the hearer would assume that the speaker must have certain reason for uttering this. And the speaker could not be saying this unless he thinks that she is no longer young and should do something or not do something. The second part of the sentence validates this assumption. Therefore, the possible implicature of this utterance may be a complaint of "she". Similarly, as for the second sentence, "only" is probably intended by the speaker to imply that she is still very young and it is reasonable for her to be bad at doing something. Attached to the first part "she has done it very well" as the semantic content, this assumption by the hearer is thus confirmed. The corresponding implicature is thus that this is a praise to "she".