@5stressed you are doing incredibly well. The most recent time we found this out about a family member (family member 2 of 2, the first one was several years ago). I literally didn't get out of bed again for about 4 days. I mean, I did, because I have 2 young children, but I couldn't work for about a week. I couldn't sleep, but then I couldn't get up in the morning either. I spent a lot of time just letting them play downstairs and lying upstairs in the dark in my room. Just couldn't function. It's about a month on now and it's better, but still not okay.
I would encourage you to be open with your dh about the information you know. And I'd also say you should talk with friends about it. It isn't your responsibility to protect anyone and I've only ever found friends to be incredibly supportive when I've talked with them. I think people wouldn't have been as supportive if I'd kept it a secret and they found out later, especially if those people had any contact with the family member themselves. In some cases, this person (well, both of them) had spent time around their children too. But I've received nothing but support. I also think it makes it a lot harder to just sweep it under the rug if you've started talking about it, and ultimately, it's not something that should be swept under the rug.
These cases are quite common unfortunately that it's unlikely to make the papers unless the person is quite prominent. I don't think either family member in my case ever made the papers (hence why we didn't know - we only found out years later, after both had been convicted, one spent time in prison, and were on the sexual offenders register). These were for offences involving sexual abuse of a child (not indecent images, in one case the child was a family member). For that matter, even police and SS were not at all interested in other children in the family. They were completely unhelpful, in fact, and I would say the police were fairly obstructive. When I wanted support in relation to my own children and concerns about this family member, they pretty much said it wasn't their problem and nothing they could do to help unless I had a crime to report. So what I'm saying is that I wouldn't be too concerned about SS. They will be unlikely to be too interested, especially if you live far from each other.
If you can give each other time to decompress and some space to think, that really helped me. I did a lot of just walking out the door and walking for a couple hours to have some headspace. Running has helped me too. Just having some time to think when it isn't all about work or cooking dinner or dealing with kids.