Translation:She had just played her last role.
I put "She just played her last role." Our regular past tense is quite versatile and overlaps the other past tenses. Yet, it marked me wrong also.
P.S. for Larry 327171 below: However, I defer to Sitesurf. This is an expression that we have to learn and for that purpose it is useful to know which past tense goes with which form. “Elle vient de jouer...” is “She has just played...”. and “Elle venait de jouer...” is “She had just played...” They may accept “She just played...” as an alternative to the first one. In reality, the simple past can replace any past tense if you don’t mind being less specific, but I can see why they would want us to learn which specific tense to use here.
It does seem odd to use a French present tense of the verb “to come” to make a present perfect tense in English and a French imperfect tense of “ to come” to make the past perfect tense in English, but it is really not more strange than using the French present tense of “to go” to make a future tense. The only difference is that we also use our English present continuous tense of “to go” to make the future tense, but we don’t use “to come” to go backwards in time.
If it helps, the English use of 'to go' in the future tense is very similar to the French: 'I am going to think'. There is no sense of going anywhere in the sentence. We do, infrequently, say things like 'I have (just) come from doing the shopping', using 'to come' to indicate the past in much the same way as using 'to go' to indicate the future. The French usage is, I think, similar to this, except that they use the present tense: 'je viens de ...'. And moving to the imperfect 'je venais de ...' moves it on step further into the past in English: 'I had (just) come from ...'.