In the US, the average height for adult women is 5'3.25" and the average height for adult men is 5'8.5". However, this varies from region to region, for example, where I live the average man is about 5'7" and the average woman is either 5'2" or 5'3", but in other places the average woman can be 5'5" or 5'6" and the average man as tall as 5'11". The heights in that statistic were taken from a medical journal where those measured were only measured in bare feet and it excluded any self-reported heights (which tend to be exaggerated), so the numbers may be surprisingly low.
So basically, you're tall but within normal range tall.
In the united states, he average height is between 5'3 and 5'4. So no, 5'7 is not average, that is tall compared to the average of women. However, depending on what standard you're measuring, you may see that as a medium height instead of short or tall. But if short or tall is in comparison to the average, 5'7 is tall in the united states.