It doesn't seem to be the problem I'm facing. I'm up to 650 Trust with jeean, still no option to take her on a date. The button doesn't even appear when I chat with her.
I assume you also miss the "asked_on_date" event for Jean like someone else earlier, while you are already much further in the relationship quest-chain with Rogue and Laura.
Basically, you only have to complete the Jean_friendship_Quest event "Jean's Friendship" before.
If you gather too quickly points, these relationship side quests get immediately solved without much notice. Uncheck "hide completed quests" gives a better overview.
As test, wait/sleep in your room for a couple of days until you hopefully get messaged by Jean in the evening/night times.
If all fails, upload your savegame here and I or someone else check it out for you. It's always difficult to get a grasp of all conditions as everyone plays and completes quests in different orders.