11 is v v young to just hope a good relationship and open talking will protect a child from all the delights the internet can throw up.
It's not just predators but the content of what goes on between friends and then also bullying.
I'm coming Out the other side of the teen years. I can honestly say 11 to 16 are tough years and we have got off lightly compared to some people we know.
Although predators are our worst fears it's also having the ability to guide them away from commenting/liking the wrong thing online. Then the peer pressure to sexy, take the piss out of others in the peer group etc etc. All normal every day teen stuff. Social media and teens can be a bumpy ride. Few cone out totally unscathed by something. Ask any secondary school teacher who have the joy of social media fall out to deal with on an almost daily basis if they would never ever check thier dc phones?
My advice is start v strict. You can release the apron strings bit by bit but it's very hard to put in place new stricter guidelines once you've started relaxed.
I have a very frank and open relationship with all 3 of my teens but I've never been naive enough to think they won't have their issues, problems, secrets they wont or don't want to discuss. We've had a few issues most of which I was able to steer/advise them away from befire escalation but bring bullied online was an issue for one of mine. I knew she was having problems as she told me but the actual level and relentlessness of it was only revealed when I checked her phone.
We always said to our 3 - here's a smart phone. We won't watch you like a hawk but just know we will randomly check your phone from time to time.We must have access to everything you use and do. That's the deal. It's that or no phone. We didn't check relentlessly just when we felt the need. Thankfully they were all v open with us. The only who k we had was the level of bullying my dd was receiving. She had told us but "didn't want yo worry us with how bad it had got".
I was able to talk through the risks of sexting/nude pics after another dd received requests for pics from some boys in the year above her and then closely monitor the situation.
I had to tell my son to remove some likes he had made on a page where the banter i felt crossed the line from joking to bullying.
My now 20 19 and 17yo now all have 100% privacy. I cant recall the day or age they were when that happened. It was a gradual process. I have a good relationship with all of them. We are a pretty open family and sometimes they share stuff with me i font wsnt to know but id ratherthat than a complete closed book.
It's not easy getting the balance right but please don't just leave her to it. Your DH is right to look. Good luck with it all. I have to say I'm glad I'm emerging out the other side but it's not all doom and gloom.