Use of JUST

[Lenora]

In this conversation:

Have you called your mother yet?
Yes, I JUST CALLED her.
(American Headway - 1B , page 105 - Liz and John Soars - OXFORD)

Is the word JUST used properly with the simple past?

BTW, I'm a teacher in Brazil.

Thanks.

[Tdol]

It's fine- the present perfect in this sense is more common in British English than American, but even in British English, the past is regularly used with 'just'.