*I AM NOT A TEACHER OR NATIVE.*
To understand the differences between the Present Perfect Tense and the Simple Past Tense, the page addressed below could be helpful:
In your scenario, although your conversation with "her" has already finished, it has some connections with the present (and even future) and therefore you can use present perfect. However, simple past also is possible and I would use it. As I know, in American English in many cases you can simply use the simple past instead of the present perfect tense.
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