Is using Google Translate, then editing it, without informing the client, considered a lie and a submission of low quality, and is the money earned from this work permissible or forbidden?

There is no harm if an expert in translation utilizes a search engine or the like, then corrects the errors to present a comprehensive and accurate translation. What matters is the accomplishment of the work. A shared employee [one who works for multiple clients] is permitted to accept a task and then delegate its execution to another, unless it was stipulated to them, or there is an indication that they must perform it themselves.