Enjoy life. Open D lets you take a break from the technical work of fretting so you can play from the heart.
A guitar in standard tuning is indeed a fairly feeble instrument unless it was made by a great guitar maker. Open D reaches the soul. My guitar store guy calls Open D with just 1 and 6 tuned down "Drop D". Try: "The Art of Fingerstyle Guitar: Solos in Open Tunings" by Stefan Grossman, with arrangements by John Fahey and others, published in 1984 by Mel Bay, Pacific, MO 63069-0066. Open-chorded tunings of any sort are a great kindness for a child's guitar.