So, I'm running a 5th ed. D&D game, and it's centered around a very Lankhmar-style city (or, for those who've played 7th Sea, Freiburg). The campaign is very intrigue-and-politics, and the PC's are currently trying to raise 42,000 gold to save their home.
To that end, one of the PC's, who when not adventuring is a courtesan, has decided to use her (extensive) contacts in the industry to host a little gala party to raise funds to get the PC's out of hock.
Last session, the player of said PC couldn't make it to game, and we agreed that her character would be out setting up things with her contacts. I further told them that I'd have some things she might've overheard or learned while setting things up.
The player loves intrigue and scandal and the like, and I'd like to give her some tidbits that she can hold or use or just be amused by as she sees fit. It doesn't all have to be courtesan-related, of course. Just things she might learn.
Anyone have any fun ideas?

Sounds like fun! Mayhap one of the NPCs has a potentially embarrassing sexual peccadillo regarding which he or she would be willing to "donate" a handsome sum in order from keeping it to come to light. As to what it might be, I leave that to your creativity (and the maturity level of your game and players). :)

How about information about a business deal between two merchants or a political deal between two politicians, both discussed in front of the courtesan on the arrogant presumption that she wouldn't understand such matters.

That lady who's just got the status to get away with refusing to tell her noble family whose baby bump that is? Everyone thinks it's that notoriously rakish guy she hangs out with, but actually it's someone incredibly important plot/politics wise, to whom said rake owes a favour. Only the lady's maid (courtesan's buddy) knows this.

Courtesan has enough contacts to put together and realise that the up-and-coming young noble from off East who's trying to marry an eligible and wealthy political keystone is, in fact, using loans for credit on other loans and pulling off an elaborate Great Gatsby scam.

That supposed three-way feud among certain feisty younger members of rival houses, which has involved mild injuries, public humiliation, one kidnapping and terrible insults to family and dignity, is not, in fact, something plotters can leverage like they think they can. It's a perfectly consensual kink game carried on under the elders' noses, and all participants are loving it.

The nice little old lady who's a holdover at court from a powerful husband who died a few years back still has a nice stash of poison if you need it, dearie, and can get you some very interesting substances in return for a favour or so.

That couple married for political advantage who live in a villa beside the batchelor pad of two gentlemen reknowned for wealth and taste are both carrying on affairs with said gentlemen, to everyone's satisfaction. This arrangement was founded before the marriage, and there's a secret tunnel under the villa wall that comes out in the orangery/middle of the single guys' dining room under a fancy grille.

Contact #5's horribly inbred pedigree animal is going to have its babies ready for adoption soon - if Courtesan wants one, she can have one. It will be worth a lot to collectors but might also die of genetic defects if not watched like a hawk and pampered like a soufflé.

The relative of someone important has been sneaking out at night to catch and eat various bugs. Whether they're cursed or going senile or insane, the contact is very worried about them, especially with their place in city politics. Aside from the nightly jaunts, the relative seems fine. They get a terrible blank look and immediately forget all mention of the subject if questioned, however.

Rebellious Scion Flirting With Revoloutionary Politics might have actually met someone who knows what they're talking about, though it's not clear whom and they're not telling. The upper-class rebel is too earnest and daft to be a danger to the establishment in themselves, but how long have they been leaking information, and in which direction...?

Throw in a rumor or two that give the PCs leverage over someone in power [captain of the guard, minor lord or something].  But then I would mix in a rumor that is seemingly innocuous, and tie it to something huge that is going on in the story.

That way, later, as the pieces start to fall together ... they'll have an 'aha' moment and be able to use the little tid-bit you gave them.

Courtesan's friend says that haughty eleven master of arms employed by Important Person and never seen without gloves got silly on some kind of herb recently and let friend scratch their head...turns out they're a drow painted beige. Friend hasn't let on they know, and is scared of what might happen later.

Seducing that one priest is really worth it.

Someone at the party has made a project of trying to domesticate rust monsters for military purposes. This person could be persuaded to help the party in exchange for access to new sources of scrap metal.

That important guy over there is being sought by someone not often seen in the city, who has recently found out he's the reason they don't look like their (half)siblings/their dad never really liked them, and is a lot angrier about it than their mother. This person is too honourable to be bought off, and they're getting close.

The rumour that there's a pet vampire in those nobles' big old house who guards their interests and eats their enemies isn't true - they're just overprotective about their albino seven-year-old, who has got extremely good at sneaking about the house in low light conditions. She's very lonely.