"but her other LLC generates no income only inventory expenses. How could I do that?"

It's not Reality. You know that.

The goal for any business is to show the income and the related costs that generate that income. That's a fundamental part of all of this.

"so I have to file 2 LLCs tax returns"

The Fed is filed using one Schedule C. Tell her why this is going to be combined. Then, have the person fix this situation, and whatever she paid for that guidance, I would recommend she gets a refund from that person. And then finds a better consultant.