When Pippa first showed she had the ability to raid Mori, I had a few thoughts as to why Mori might be following her, but then it was revealed it's just because of it no longer being whitelist, so I put those thoughts away... but here we are, Mori clearly knowing about Pippa and even using her catchphrase correctly.
So my suspicion mainly lies with /vt/. Mori, as shown in her VA-11 HALL-A streams and the NSO stream, has an issue with egosurfing, but particularly on 4chan/imageboards. Given this, I suspect she lurks, possibly even posts there regularly, under the guise of being a fan.