Work backwards from the date she must be productive in Ohio, allow for a request for evidence, and file early enough that premium processing is a choice rather than a rescue.
Build the schedule around the evidence, not the season
The pressure in a seasonal business is to file late and pay for speed. That works only if the evidence is complete, because premium processing commits USCIS to act quickly, and acting quickly can mean issuing a request for evidence quickly. The specification documents, the authorship trail and the human-resources letter naming the qualifying year take longer to assemble than most companies expect, particularly when the employee is the person who would normally assemble them. A workable sequence is to gather the evidence first, decide the filing date from the readiness of that evidence, and hold premium processing in reserve for the gap between readiness and the date she is needed. She should not begin the Ohio role before approval; work performed in the United States without status is a problem no filing date can fix.
Hypothetical example: a plastics-extrusion company wants its process specialist on site for a launch that is eight weeks away. The first review should start with the dates of the qualifying year and then test whether the knowledge exhibits can be gathered and explained before the petition is filed. Payroll, version histories and manager declarations settle readiness. If they are not ready, change the launch staffing plan or defer the transfer; premium processing can shorten an adjudication period, but it cannot manufacture proof of company-specific knowledge.