If the twelve continuous months are clearly documented, file. If continuity depends on an arguable period, waiting a few months until the year is unquestionably clear usually costs less than defending a marginal claim.
Waiting can be cheaper than arguing
Hypothetical example: a Hampton company has a customer rollout scheduled and wants to file immediately, even though its consultant's first seven weeks were through an agency. Filing now means the petition rests on a period that may not qualify, and a request for further evidence on that point would itself consume more time than waiting would have. Two months later the same claim is unarguable.
Set the decision out plainly: what the rollout actually requires, whether a colleague already holding status could start it, what a request for evidence would cost in elapsed time, and what waiting costs commercially. The one option to rule out is having her perform the U.S. work in another status while the petition is pending, which contradicts the petition itself.