The use of "since" and "for" with the Present Perfect Simple

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Hi
I would like to know more about the use of "since" and "for" with the Present Perfect Simple.
I have found that these expressions are mainly used in the Present Perfect Simple in order to show a continuous situation, (especially with stative verbs that most of the time are used only in the simple tenses) and with negation. However, it seems to me that these expressions give the Present Perfect Simple the sense of "progressive" in other cases as well for example: "She has kept a dairy since she was 10 years old".
Does this mean that she is still keeping her dairy? If so, how is it different then from the sentences in the Present Perfect Progressive: "She has been keeping a dairy since she was 10 years old"?

Thanks for any reply