"I don't suppose you can throw in reversible sterility." 

"Unfortunately the cheapest option I have available is using a later body modification to reverse it. You could easily earn enough in a year or two, but it is still a thirty gratitude expenditure."

"Yeah, if and when I choose to up my contract again that'll be small potatoes. And I shouldn't be deciding to have children anytime in the next few years, I'll have much bigger fish to fry. So I think I'm comfortable saying you should make my new body sterile by default." 

"... Especially because that'll make it a lot easier to explain," she adds. "I haven't really thought about what I'm going to think about the body change given that I'll be unaware of the contract. Do I have to be concerned about keeping my legal identity, or is sorting that out part of the package? I'd like to lose several feet in height along with the genital replacement, but that kind of thing is likely to, uh. Cause problems." 

"One of the consequences of my Queen's edict to deal fairly with mortals is that we cannot cheat the identification problem directly, inconvenient though that may be." She smiles wryly. "My best idea there is to arrange for your transformation to Inexplicably Occur in front of witnesses such as a doctor or government official who has already verified your identity."

"How many of these contracts are you doing? Is hell, uh, going public? I kind of don't want to be the only person other than the pirates this very inexplicable thing has provably happened to. That seems likely to cause all kinds of trouble."

"We do not have any plans to issue press releases per se, but we are putting the rumor mill to work regarding the existence and reformation of Hell, and the existence of magic. You are not the first person to opt for a magic transition, though by and large previous contracted individuals have opted to play it off as implausibly effective hormones. The contracts will never become common knowledge, of course, because that would destroy their effectiveness."

"Yeah, that makes sense. Uh, hmmm."

She considers for a long moment. Does she want to be the center of a media circus, or does she want to compromise on her ideal body...?

She is kind of already compromising by staying human.

And there are other supernatural creatures out here. That is pretty significant. 

"I think I am going to take a relatively restrained transformation that keeps my height and my, uh, being a human, if not my body features. I think anything in this category is going to be... awkward... and I would rather be able to retain my original identity without too much fuss, much as my soul cries out to be a foxgirl. I particularly don't want to attract the attention of other supernatural creatures that might not have my best interests in mind." 

"Reasonable decision. Assuming you stick with both the monthly frequency and the new three-demon encounter density you've been considering, you'll be able to afford both a new transformation and a Demon Sign to mark you as under our protection in under four centuries. The number may seem large now, but it's truly not long, from the perspective of the ageless. By that point magic will almost certainly be extremely well-known, so further transformation will not surprise anyone by then."

She hums softly. "And you may find yourself comfortable with an expanded contract between now and then, which would shorten the timeframe dramatically."

"Yeah, I'm more or less betting that I'll expand the contract again in a few years now that I will actually know what's going on. The process will be messy but we'll get there, I think."

"I don't know if there's any life milestone checkin that would make sense at this point, honestly. Do you have any suggestions on what to spend my handful of spare points on?"

"Honestly my advice would be to bank those for the future, at this point. You don't have enough leftover to add an additional condition, you already have the most frequent interval-based option, and nothing else is under fifty gratitude."

"Alright then, let's do that." 

She takes a deep breath.

"Is this where I say 'see you in two years'?"

"Almost." She snaps her fingers and presents the revised contract for Ava's review and signature. "Just need to get this formalized first."

Ava reviews it, and points out one error - the Check-In Condition she had set for conception is still in the contract, and is no longer necessary - but the whole is sound. She crosses out the small section, then takes a breath and puts her signature to it. 

And the negotiator smiles warmly, takes the contract, and sends it back to the archives. "It's been a pleasure, Ava. See you in two years."

Ava closes her eyes, expecting a sudden discontinuity —

And she wakes up in her bed, the dream completely forgotten until her next check-in.