We are into the realms of grammar policing over a sex offender, when we start talking about the definition of a paedo - all in order to 'win on the internet'.
That's pretty grim to me. And naive. And gaslighty in its own right.
This is a sex offender. It doesn't matter if you only have boys and the sex offender only targets girls. There is still the risk of grooming behaviour and normalisation of acts which are not acceptable which means other people might be at risk in the future.
We know that sex offenders do not only offend sexually. Part of their behaviour is emotional abuse in order to justify their behaviour or to get away with their behaviour. Lying and manipulation is part of sex offending. Often it's part of the thrill.
The whole point is you need to protect anyone vulnerable from this behaviour - all elements of it. That includes the bullshitting.
What's striking about the OPs scenario is precisely the point that her brother has been employed as a flying monkey to try and force his sister to allow their father back into the lives of the grandchildren - using emotional blackmail and abuse.
This is about healthy relationships and family dynamics all round. A sex offender simply doesn't have that - even if they aren't offending against their own family or ever likely to. They will be aware of what is likely to happen to their family if they are caught. They just don't care. The narcissism it takes to be a sex offender is, in itself, a bloody good reason to avoid an offender you have previously been closed to. And the risk is you stick by an offender and they do it all again and drag you all through the process again. That should be enough to make you run for the hills, and if it's not you really should be looking up FOG and seeking professional health in how to break the cycle of being vulnerable to emotional abuse.
For all the talk that 'oh I don't think I could cope, I'll kill myself ' - there's never any regard as to how family members will cope emotionally if they find out a close relative is a sex offender and how that will impact their lives and that's the thing you always should focus on. It destroys lives.
I know a family who has been affected by the subject. Kids are tweens. There's the embarrassment and shame and there's the school gossip and there's impact to what activities the kids do and who they are allowed to see and who will still play with them. It's enormous. The family are being well looked after by friends and extended family and he's no longer welcome fortunately. But it's been devastating to them.
He, of course, span the suicide thing to his mates too. What was notable was what he did - approaching certain people but not others: the ones I would describe as soft touches and not the ones who don't do bullshit. Even in this he was being manipulative and thought he could worm his way back. Fortunately, the sensible heads got wind and they told him to do one which meant the soft touches followed suit. It was an interesting real time demonstration in personality dynamics. Miraculously I believe this guy is still breathing despite all his suicide threats, though he has moved away from the area.