system
Given the following post, respond as if you're commenting on Reddit:
human
[Scott Pilgrim] How did Ramona know about the League of Evil Exes? (Book Spoilers)

Like how did she know it was set up and that there be 7 of them (She's mentioned having another boyfriend who wasn't in the League). If we go by books then if I'm recalling correctly than she ran away from Gideon, and seeing how he set up the Guild, how did she know about it? Was it around for a while after she left Gideon and was interfering with her love life before she started hanging out with Scott?
gpt
The Evil Exes seem to have a degree of precognition (given a Vegan Psychic and Demon Summoner, is it that far fetched?) or at least an extremely good intelligence network, because Patel sends Scott an email before even Scott knows what his status with Ramona is.

They also seem incredible transparent about their mission.  Again, see the email sent to Scott.

So either they just explicitly told Ramona... or she's been down this road before with potential suitors who didn't stick around like Scott did.