The conversation Velma had with Giselle did not, in any way, shape, or form, touch upon the topic of romantic interests despite that being one of Velma's favorite subjects. Instead, they talked about Giselle's past.
When she first reached out to Velma, after the initial pleasantries, the first thing Giselle asked was how Velma learned about her past. The answer was as she expected. It wasn't that Lex had divulged anything.
Instead, with so many orphans and children living and operating out of the Midnight Inn, Velma naturally took notice. When it came to intel about people, even the mass surveillance of companies from back on Earth paled in comparison to Velma.
Of course, she didn't do it for malicious reasons, or to spy on anyone. Instead, she just had a deep and genuine love for learning about people and listening to gossip.
