I have a niece who posts photos more to Instagram than to the family group chat (2/3 iPhone, 1/3 Android). I don't have any Facebook apps on my phone, tablet,

I have a niece who posts photos more to Instagram than to the family group chat (2/3 iPhone, 1/3 Android). I don't have any Facebook apps on my phone, tablet, or computer. I use Instagram and Facebook with Firefox with them locked to a Facebook container. For Instagram, I use User/Agent Switcher to tell it that I'm on an iPad using Safari. It works well except that Facebook won't let me set up two-factor authentication and asks me every time to download the app. Every once in a while Facebook asks me to join the Facebook and Instagram accounts and I refuse to do so. I assume that they're combining the data anyway. But Facebook does let me use a security key as 2FA and I don't want to lose that. The major downside is that I can't post to Instagram. But that would bother me more if I were a better photographer or my kids were younger than teenagers. I also use Fluff-Busting Purity (formerly Facebook Purity) and two kinds of ad-blockers (AdGuard DNS on the router, uBlock Origin in the browser).