The easies thing to do would be to give her a copy of TalkOrigins' Introduction to Evolutionary Biology. It's excellent, and not too long. It may overwhelm her, though, so if you'd like to write something of your own, I'll give some suggestions. I used to argue with creationists as a hobby, so this is kind of nostalgic for me.
What kind of creationist are we dealing with here? Is she a young-earth creationist who thinks the world is a few thousand years old, or an old-earth creationist who won't choke on basic geology? If she's an old-earth creationist, I would suggest reading up on a few fun geological processes that took longer than she thinks the earth has existed. One thing in particular to mention is how we do radiometric dating; a lot of creationists have this silly notion that we try to carbon date everything, no matter what the time-span, and that there's no corroborating evidence for any of it. With few exceptions, these people have never heard of things like potassium-argon dating or the geomagnetic polarity reversals that mark time on the sea floor. Or dendrochron calibration, or the passing of the seasons recorded in ice sheets. If your friend is a young-earther, infodumping about this stuff in a basic way should be moderately upsetting to her, in a good way.
General advice that applies to all kinds of creationists: if you're not going to be arguing back-and-forth with her, then you should try to make her feel doubt. For example, you could quote the head of the Human Genome Project, Francis Collins:
As someone who's had the privilege of leading the human genome project, I've had the opportunity to study our own DNA instruction book at a level of detail that was never really possible before.
It's also now been possible to compare our DNA with that of many other species. The evidence supporting the idea that all living things are descended from a common ancestor is truly overwhelming.
I would not necessarily wish that to be so, as a Bible-believing Christian. But it is so. It does not serve faith well to try to deny that.
But I have no difficulty putting that together with what I believe as a Christian because I believe that God had a plan to create creatures with whom he could have fellowship, in whom he could inspire [the] moral law, in whom he could infuse the soul, and who he would give free will as a gift for us to make decisions about our own behavior, a gift which we oftentimes utilize to do the wrong thing.
I believe God used the mechanism of evolution to achieve that goal. And while that may seem to us who are limited by this axis of time as a very long, drawn-out process, it wasn't long and drawn-out to God. And it wasn't random to God. [He] had the plan all along of how that would turn out. There was no ambiguity about that.
There are compelling arguments you could make against the idea of an intelligent designer shaping evolution -- the design mistakes, the existence of horrific parasites, the breathtaking cruelty of certain parts of nature -- but it would be a victory if you could just get this friend to admit that evolution happened at all, God-guided or otherwise.
Give her a glimpse of the mountain of evidence that she's denying. Talk about fossils, and mention the standard rebuttal to the "no transitional fossils" nonsense. Touch briefly on modern phylogenetics, reconstructing the tree of life by looking at patterns in the genes of living animals. Find some specific examples of coevolution between species, and exposit. Richard Dawkins' books tend to be excellent sources of detailed examples, presented with his usual cheerful enthusiasm; I recommend them.
TalkOrigins is a treasure trove. Some especially useful pages are their FAQ listing observed speciation events, and the list of crappy designs in nature. Also useful is creationtheory.org, which is more focused than TalkOrigins and an excellent resource. You might also try explaining why evolution does not violate the laws of probability, which is a very common creationist argument.
Good luck planting a seed of doubt. That's all you can realistically hope to do right now, so don't get discouraged if she doesn't change her mind right away.
Speaking of talk.origins, here's a really nice example of common descent (and a few other things). Not sure how suited it is to this, though.
I have a creationist friend with no particular rationalist or scientific training. She recently asked me to send her a "list of evidence for evolution that persuaded me." After some prodding, it was revealed that she's getting into an argument with another friend of hers who believes in evolution. I'm assuming that she wants the experience of arguing with someone who's on level footing with her. It seems like a good opportunity to broaden someone's mind in a more general way that'll benefit them in the long term. I don't particularly care whether she believes in evolution (it probably will not impact her or the world in general if she changes her mind about it). But I'd like to phrase my e-mail in a way that's most likely to cause her to re-evaluate her worldview.
Subgoals related to this:
1. Point out that "losing" an argument can allow you to learn things, and if you honestly care about truth you'll try your best to evaluate ideas from other points of view and consider what it would mean if they were true. Do this without sounding condescending.
2. Give her a line of retreat by proposing that evolution is compatible with the Original Sin interpretation of genesis (which is very important to her and I would never attempt to argue against).
3. Give as much background as possible on the scientific method.
4. Still manage to focus the bulk of the e-mail on the most persuasive facts supporting evolution, otherwise I'm obviously not satisfying the criteria she actually gave me. I don't mind taking advantage of her request for my own purposes, but only if I'm actually helping her with her stated goal.
5. Specifically show why macroevolution is not only possibly but likely. (I'm pretty sure she either already believes or could be easily persuaded to believe in microevolution)
6. DON'T focus too much on why creationist arguments are flawed (she hasn't even used any yet, and it sends the wrong message about trying to actually figure out what the truth is)
7. Accomplish everything in approximately 3000 words, without using jargon, designed to be read by someone who's mental architecture isn't particularly adapted to rationalist thinking. (Most people aren't.)
I believe I can do a decent job myself. But it'll be a fair amount of work, and I want to know if anyone had a recommendation for a particularly good essay that I can either link her to or borrow pieces from. I might also include a link to a page of common bad creationist arguments and why they don't make sense.