Assuming 40 hour weeks, 2 weeks vacation for 4 years, equals 200 weeks equals 8000 hours.
$70,000 divided by 8000 hours is $8.75 an hour.
Or $17,500 a year in salary. If she only worked at the quilt for half time, its still only $17.50 an hour. That is a very small sum per hour for the innovation, expertise, skill and design, not to mention all the materials involved.