Hi Kate ... I think you need to ask yourself how you feel going back now that you know TTATT. If you can stomach it then sure.
I honestly have a very difficult time stomaching a KH. One of the reasons for me is that the local pedophile is still in my Dad's previous congregation. Back in 2010 was the last time I attended that KH and yeah, that douche bag was there. I had to go to take my Dad to a funeral... I mean 'memorial service/advert for JWs' for one of his friends (Dad wasn't able to drive at that point).
If I were in your shoes I'd suggest to my loved one that we meet after they've gone to their meeting to discuss things. Of course, if what you are discussing is the JW meeting then I guess you probably should go.
I would not. But that's me and my circumstances/stomach.
Let us know what you decide and how it goes. Maybe try it once and see?