This is true. I couldn't believe that either, and I like the character.

The thing is, when she died, her mother headed a crusade against Batman on national television for 'killing her child'. So when they needed the retcon, they had to make it so the mom never knew that Stephanie was alive or none of that story would make any sense.

I just tossed everything from when she became Robin to this mini-series, just like I pretended Bruce never launched Brother Eye or gave Tim that crazy mind-games box for his birthday, or . . . well I have to toss a lot of what Bruce did.