I wouldn't say they "ignored each other," because the DC Annual came out a year earlier, so they wouldn't have been aware of the book's contents anyway. Being unaware is different from ignoring. For that matter, McIntyre probably wouldn't have been aware of the comic's contents until after she'd gotten her outline approved anyway, unless there'd been deliberate editorial coordination.
I'm sure I read an interview where it was said that Vonda had a chance to consult but she didn't wish to. So the two projects continued independently.
That doesn't make sense, though, because "Charlie X" made it clear that Janice was way too mature for the 17-year-old Charlie Evans (at a time when McIntyre's version of Rand would've been physiologically no more than 18-20, and chronologically only 2 years older than that, IIRC). The show's Rand was clearly meant to be around Kirk's age, and thus around Whitney's age.
Exactly. But Vonda was definitely trying to do something with Rand's age and appearance.