Nada's implying that they're under-planning and making light of pilgrimages (this strip plays off of the difference in meaning of pilgrimage to Miracle+Kevin and Nada), as she's been preparing for much longer than they have.
She says "メッカへの巡礼は予約10年待ちなのよ! // もっと計画的にしなさい!," more literally "I've been planning (and waiting for) my pilgrimage to Mecca for ten years! // Be more systematic!"
I suppose "Be more methodical!" might have made more sense.