First, I'm a bit unclear: Is this your future plan or what's "not working" right now? Hard to imagine a 90 pound female not gaining on close to 2400 cals per day. Typically, most resistance-training individuals only need about 800 to 1000 calories over true maintenance levels of calories to fuel optimal muscle gain. Any more than that and you're just adding unnecessary fat that doesn't lead to more muscle gain than 800-1000 cals over.
Other questions: How long have you been doing this, assuming you've started? The Carb Care article you referenced is only a week or two old, so I have to wonder how soon you decided it wasn't working.
What's your training like i.e. does your training reflect your goals?
Don't be afraid to hit 150g carbs using the Carb Cure basic premise. There's wiggle room there.
It's very easy to add calories without reaching for toxic food and junk carbs. Lots of meal ideas here: http://velocity.t-nation.com/free_online_forum/diet_performance_nutrition_bodybuilding_velocity_recipe?pageNo=1&s=forumsNavTop
At 90 pounds, it doubtful you're an easer fat gainer. You may not need something like a Carb Cure plan, though there's never a reason to add junk.