Did she have any pains while riding the 4 hours, or just started having some the day after? I like the other posters suggestions about getting her fitted by the LBS, or by taking pictures and posting them here.

I will also echo others sentiments that riding 4 hours at one time and not riding previously will produce some pain.

Also, what is the extent of the pain? Is she pretty much bedridden or can she get by with just some advil and just complains about her neck and back?