AFAIK, assuming there actually IS the OG PG out there---I don't know that she'd even know Jon or really any of the extended Super Family. She barely knows Clark and other Kara, and AFAIK only met Jon once or twice, and that quite some time ago. And does she even have any reputation with anyone on the main Earth? I just really haven't heard her being mentioned much. To me sure, if she's actually there, and what she was prior to Flashpoint, she should be the one leading the charge, or at least one of them----that's what she's done in other stories. Nightwing, Alan Scott, Mr. Terrific and PG seem about the most experienced leader type heroes left.