Just reading this, I can't believe what an awful little cult the WTS is.
So, an in-law just 'stumbled upon' your web history did she? More like actively checked what you had been legally viewing on your personal computer.
I'm sorry that this will negatively impact upon you and your daughter.
Denying is only an option if you've been very careful not to post anything that will identify you. The elders will go through all posts made by pale.emperor to see if it's you.
As Kairos said, report this to the local authorities as an invasion of privacy. The elders might back off if you involve the law.
PS - I'm definitely not pale.emperor.