Or a contract that is...
Question of the week: Do you always ask for a contract if the publisher doesn't mention it in your initial contacts? What if they say 'no!' Update to this question: I haven't received the contract despite an impending deadline...what should I do?
Truth told, in recent years, I've never worked for a magazine or client who hasn't offered a contract, but yes, if one isn't mentioned in the initial email or phone exchange, I would simply ask, "When can I expect the contract, as I'd like to get started on this right away." This implies that a) you have the expectation of establishing proof of assignment and terms of said assignment and b) you're still eager to tackle it but won't tackle it without documentation.
If they say "no?" I'd walk away. Because if someone firmly refuses to give you contract, even something loose like putting the terms in an email, then I'd think the publication or editor was dodgy.
That said, I certainly have started working on assignments before I'd received the actual contract, but only for clients with whom I have an established relationship. For example, I write often for a certain magazine that has very tight turn-around times and requires hard-to-nab interviews. I've been writing for this client for years: there is no doubt that they'll pay me and pay me promptly. By the time the editor gets the contract request into whomever processes the contract, I'd have long missed my chance to nail down my sources. SO. In this case, I move ahead, knowing full-well that everything is on the up-and-up. Some writers won't do this. Some insist on waiting for the written contract, and I understand why they do this, but for me, it works best to be flexible and make certain exceptions.
In your case, however, this is a first-time client (as elaborated on in the email), so I'd never proceed until something materialized. Now, with a looming deadline, I'd send her another note or better yet, pick up the phone and say something sweet yet pointed, along the lines of, "You know how excited I am about this project but I simply can't proceed without a contract. As you may know, my deadline is imminent, so in order to complete this on time, please let me know when I can expect the contract." If your editor still hedges, I'd take it as a much bigger sign of problems to come with this publication, and I'd walk.
Readers, what say you? Do you work without contracts, and if so, have you ever gotten burned?