She is in a relationship with Unmid Snow-Shod, the Jarl's housecarl, as a conversation between them reveals her calling him "lover" and to "meet her in her chambers", though this is never elaborated on. She is also heard asking him if they will be meeting later for "...combat training?" with a very suggestive inflection put on the "training."
Recognise this? (Show her Incriminating Letter)"Not here, come with me. Stay close and the guards will leave you alone." "I suppose you're here to extort something from me? Is that it?"
You rebels are doing a fine job destroying yourselves. Soldiers running errands?"So you're an Imperial spy... Interesting... I have no strong love for the Stormcloaks but I can't say I'm all that fond of the Empire, either. This war of yours is making it difficult for a resourceful woman to advance her interests. Perhaps we can find a way for both of us to prosper from this unfortunate discovery?"
What if this letter were made public?"It would ruin me. I have a good thing going here. The Jarl benefits from my more creative arrangements as well, though it'd be impossible for her to admit that. Laila is a simple and traditional woman. Which makes it easy to manipulate her, but impossible to regain her graces once offended. Look. Perhaps we could come to some kind of agreement?"
What kind of agreement did you have in mind?"What if I told you about a large shipment of gold and weapons?"
Go on, I'm listening."Oh no. I'm no fool. You'll learn what you need once we've come to an agreement."
How much are we talking about?"Enough to make a significant difference in the war."
And what about something for me, right now? (Persuade) (failure)"I don't think so. How do I know you won't continue to extort me? A wagon full of gold isn't good enough for you?"
(succes)"Well I... I suppose I'm not much left a choice in the matter, am I? Very well. I trust a hefty purse of septims will suffice?"
All right, it's a deal. Where can I find this shipment?"They're taking it by wagon to Windhelm. If you hurry, you'll catch them before they get far. It'll be a fairly slow moving caravan. The shipment is quite heavy, and guarded by many men. Now, let's pretend we never had this discussion."