In Doomsday Clock, when Manhattan undid his alterations and restored the JSA, Pre-Flashpoint Power Girl was with them. So assuming he's the one who trapped her there, he released her.
Tanya is in getting a cameo in the Future State Shazam book. So presumably Manhattan also released her alongside Karen. Makes sense.
And we're still waiting on the JSA relaunch with returned team from doomsday clock(which should have Karen). They were suppose to get a guest appearance in Geoff John's Shazam series but it was cancelled before they could appear.