Hey Eric. I build ASOScan, an app store optimization tool for iOS and Android, so fair warning I'm biased. Your daughter's right that social helps, especially for a launch bump, but for paid games with no ads the channel that keeps paying off is App Store search itself. People search the store and buy what shows up, so a lot of it comes down to making sure your games actually show up.
The main lever is your metadata: title, subtitle, and the keyword field. You want the terms players would actually type for your kind of game, ideally ones with real search volume the big studios aren't already sitting on, then you watch where you rank and adjust. It's worth keeping an eye on your ratings and what similar games are doing too, since both feed into how you show up.
Happy to look at your three specific games and tell you what I'd change.