If a 2 mth old puppy is not eating, I would take her to a vet. I would never let her starve until her survival instincts set up.
Purina is a garbage food. You can do much better for just a little more money.
As far as feeding, I put the food down and give them 15 minutes. Nothing wrong with having a schedule.
~The strength of one's opinion should not exceed their knowledge on the matter~