I know I'm late to this, but wanted to toss in my two cents!
Your friend really needs to decide if she wants to self publish or go the publisher route - obviously there can be crossover between the two but it's less common. There's pros and cons to both, but really, it's up to her and what she wants to do. Self publishing is quicker, but harder to be noticed in the grand scheme, unless she's really good at self promotion and social media.
If she does want to go the publisher route, she really needs to be honest with her self and her book's potential - not every book is going to be a home run, published by the Big 5. And that is absolutely okay. If she's gunning for mass production/sales, then she'll need to hook a literary agent. Which also means she'll need to learn how to do a query letter. But sometimes a smaller publisher will suite her work just as well. She should also look at what type of book each company publishes and hone in from there - you don't want to send like adult fiction to a kid's publisher, etc etc.
I would recommend Jane Friedman's blog. She's quite helpful, succint and thorough on these kinds of topics.
Jane Friedman has 25 years of experience in the publishing industry, with expertise in how the digital age is transforming writing careers and storytelling.
www.janefriedman.com
Also, she shouldn't bother much with the publisher search until her novel is completed. Most places won't even look at you unless your manuscript is DONE. And I mean like fully edited, done, not just written out. Unless she wants to self publish, in which case, you can submit what you want when you want - even having multiple versions of the same book. I know Amazon is a popular outlet for self publishers.
Anyway, hope this helps some! Good luck!