I would totally skip the ‘just/juste in both English and French’.

I saw Sue yesterday/last week.

J’ai vu Sue hier/la semaine dernière.

Just/juste are not really formal.

Juste has several functions (adjective, adverb, noun) and meanings. Here it can be used to mean seulement or précisément.

• Juste might mean seulement et exactement (only and precisely):

Je l’ai vue juste hier / juste la semaine dernière. (colloquial)

Je n’ai vu Sue qu’hier / que la semaine dernière. (i.e. I didn’t saw her before or after).

• You can also use juste to mean the event happened in the very close past, almost the present:

Je viens juste de voir Sue.

You cannot use the same expression if the event is older. In this context, one day or one week are not compatible with venir juste.