How do I change ownership of a family business in turbo tax? I need to know how to end the business on her taxes and add it to mine.

How is the family business organized?  sole proprietorship, partnership, S-Corp, or Corp?

sole pro llc

Im talking tax wise, what do I have to do.

You should get legal advice about changing the ownership of the family business, particularly since it is a sole proprietorship.

A sole proprietorship is tied to its owner. Legally they are the same. There are no registration requirements to transfer the business; however, some legal aspects of the transfer deserve consideration.

For a discussion of this topic, please see the following article: 

How to Transfer Ownership of a Sole Proprietorship

And since it is a state registered limited liability company, your state may have legal paperwork to process.  Up to dissolving the existing LLC and creation of another.  While a single owner LLC is a disregarded entity for federal purposes, it likely is not to the state.

I understand that I'm talking about tax wise how do I do that.

You basically enter a new Schedule C with you as the sole proprietor.  It is a brand new entity.  On the previous proprietor's return she enters that she stopped doing business in 2018.