I would recommend classic, but that is also my bias as a Norwegian.
It is easier to go easy in classic, especially when you are new to the sport.

thanks, probably classic then because I'm pretty sure she wants to keep it pretty mellow

Start with classic. Learn speed control and weight transfer. Take lessons. Buy decent equipment, dont just go to some alpine store, go to a good nordic store.

Canadian Devin Kershaw did the classic race at Beitostolen last weekend. According to him only one person in the top 30 used grip wax.
Skiers are so much stronger in double poling.

From Fasterskier http://fasterskier.com/...start-to-the-season/

“I am pretty sure [France’s Maurice] Manificat [who placed 16th] was the only one in the top 30 on wax,” he wrote. “Then me in 33rd after that. Everyone else double poled. It was much faster (to double pole) but having not skied much, and racing on borrowed skis (I only had two pairs of skis total) my options for testing were limited. I didn’t even test double poling to be honest — again, because I didn’t have a lot of choice (instead one pair had klister, the other klister-cover).”
While he regretted his choice of wax, he explained the rest of the ski world should be well-aware of what’s happening to cross-country skiing.
“In case there are any doubters left that the sport is changing, [the Beitostølen 15 k] should be the final wake up call. The frying pan between the eyes so to speak,” he wrote. “So many people double poled, over 50-60 guys in the field. They are strong enough to do that on a course with over 400m of ascent over 15km without hesitation — and win big — double poling only.”