I am guessing but is that a hammer in her hand and she looks like she wants to someone a very bad day
Either right after Pearl Harbor (Enterprise would be pissed off and go hunting), or near the end of 1942 when both sisterships have been sunk and with Saratoga being repaired, Enterprise is all that is left. She's as repaired as she can get until the middle of 1943 when she finally goes home for real repairs, leaving Saratoga as the lone fleet carrier (until the British send Victorious, and then the first of the light carriers and Essex-class ships start to arrive in the Summer and Fall).
Do we have a tag for these non-kantai collection ships? I thought they were called battleship girls?
This is technically a Kantai Collection ship in that Pacific is a fan expansion to the KanColle universe by jeanex and his circle. So the current tagging is correct.