By the end of issue 25 of World's Finest, PG and Huntress were sent back to Earth-2. The young black woman pulled the switch on the portal-generator, and PG left her the name and company.
Their story continued in the Earth-2 books>Harley Quinn
The HQ book, since 2011, has been very loose with canon. It's easier to just assume that nothing in it is really connected to other stuff (the exception is when Humphries started writing it in 2018)>Deathstroke
She only appeared in the Annual issue, and was trapped between worlds. My guess is that she is like a teleporter error, where she is actually a duplicate of the one who went to E2. I nees to get the pages, but her costume is similar to the one that she left Earth-1 in.
That plot was never continued because DC rejected Priest's pitch for a Power Girls miniseries with both women.>Doomsday Clock
Hasn't been touched since it ended.