There's been a lot of research by scientists and sociologists on this so caution is the word here.
flipper do you have any source for this claim? I just find it boring and ridiculous sitting through a meeting after I woke up. You see through the manipulation and lies, I don't think it has any negative effect other than that you might get irritated. Once you know TTATT I think you are pretty much immune to their deception.
This is of curse my personal experience so some source to your claim would be very interesting.
KateWild
Regarding giving false hopes to you daughter, I think if this is a risk. Going could be a bad idea, some have had relatives reconnect with them when they realized that they will never come back. It will be a setback in this regard if you give your daughter hope.
Also, if you decide to go I would suggest as many others have. That you make it clear to your friend why you are going so there wont be any misunderstanding or any idea that you are approving their decision to become reinstated.
But as I said before, I don't see any reason to fear the JW indoctrination after learning about TTATT as many of the other posters here do. If you think you can help your friend by going to the meeting I think you could do it, but remember to include the effect this will have on your daughter before make a decision.