This will mainly focus on Ads, see this article for other aspects of your app (i.e, content and data practices) Designing Apps for Children and Families - Play Console Help
I will try to update this as SDK and networks get updated. First, there has been some mix-up(for me a least) between Google Families Policy and the new Google Play Advertising ID permission. As of writing, this Solar2d Simulator targets Android 11 (API Level 30), and this permission is not needed (yet)
Who needs to change their apps?
If your app includes kids (people age 13 and below) as a target for Google Play
What do I need to do to show ads to people aged 13 and below?
If the user of the app is 13 and below or you don’t know the age, you have to mark that with the ad provider. Also, you need to use a supported network
Currently (Known) Supported networks of Google Families Ads (Solar2d)
Admob Solar2D Documentation — Plugins | AdMob
See Solar2D Documentation — Plugins | AdMob | load params childSafe and designedForFamilies
Applovin Max Solar2D Documentation — Plugins | applovinMax
See Solar2D Documentation — Plugins | applovinMax | setIsAgeRestrictedUser and Solar2D Documentation — Plugins | applovinMax | setHasUserConsent.
Kidoz Solar2D Documentation — Plugins | KIDOZ
Unity Ads(v4) Solar2D Documentation — Plugins | unityads-v4
See Solar2D Documentation — Plugins | unityads-v4 | setPersonalizedAds and Solar2D Documentation — Plugins | unityads-v4 | setPrivacyMode.
External: Iron Source IronSource Plugin
Read More Here:Ads and Monetization - Play Console Help