From what everyone has read and combed thus far, nothing of the sorts has popped up. It seems unlikely that ILJ has directly encouraged Chris to fuck his own mom and even if that were the case, that push would be kinda like blowing air to make a boulder move. Chris has had an extensive record of incestual desires so mostly things will fall on his lap this time.
It is extremely difficult to know since these chat logs do not mention much information about her interactions with Chris. The server that leaked was her private "Chess Club" server (IRL friend group server, in actuality). We know that she was in other servers dedicated to fucking with Chris, we just do not have the details that were shared in those servers.
However, looking at the history of Chris and relating it to what has happened started at the end of June makes her pretty fucking suspect for enabling/encouraging Chris to do this, at least in my opinion.
First, we know that Chris has had sexual dreams related to Barbara for nearly a decade now. This is extremely well documented because Chris is Chris and he has no filter and will admit to this. However, nothing physical ever came from it.
Second, we know that for at least a year after the house fire Chris and Barb shared a bed and spooned each other while sleeping together. It only ended not because it made either of them uncomfortable, but because Barb thought Chris didn't fucking spoon her/cuddle her well enough. They shared a bed for at least a year and cuddled each other to sleep every night and that didn't drive Chris to fuck her?
Then, Isabella Janke comes into the picture. She is a known incest loving pedophile who loves to brag about it all over the internet. She begins talking to Chris in January, and by July he apparently "trusts him the most"
She responds by hacking into Chris's bank account and stealing his tugboat.
Even though Chris was put in plenty of situations where he could have fucked Barb in the past, he didn't. He thought about it, but didn't act upon it because he knew it was wrong. I and a lot of other people here think that she encouraged Chris to do it because she thinks that incest is some sexy pornhub in real life shit. Since Chris deeply trusted her and her opinions and is incredibly easy to be influenced by outsiders, he actually did it.