You can have multiple bloggers from one blog.
I would advise her to go the WP way, since then she can create a standards-compliant, normal webpage using php, and she has absolute control over it.
Paid livejournal accounts are pretty much the same as free accounts. I have a paid account, and I still can’t include javascripts in my pages, for one. The structure of the LJ page still has to adhere to the already available s1 or s2 styles, unless you want to understand the s2 language (which is not used anywhere else) and whip up your own s2 style, which is not worth the pain. For example, they have a developer hired, who creates s2 styles, and he has come up with 2 new ones in what 8 months? or something close.
She can keep her free LJ account to keep track of her friends if any and have them keep track of her, and with the lj-update script, updates to her blog will automatically update the LJ.
The Lj paid account might be cheaper, sure, but WP is more bang-for-the buck. Even a paid LJ account has a url like 2fargon.livejournal.com, not 2fargon.com, for example.
She can always find cheap hosts, even a free host if she is willing to settle for a subdomain. If she wants her domain, then the cost could be as low as about 2.5 dollars a month, which is about the same as that of a paid LJ account.
Go WordPress!