Hi there! Hope it's okay that I'm jumping in here, too.
It might help to clarify what "friends" means to you and what "dating" means to you, so you can set boundaries around what you want in either relationship.
If you feel uncomfortable with the idea that "friends" can sleep in the same bed, be affectionate, etc, you can tell her that - her idea of what "friends" do might be different from yours, so clarifying what you mean can help things feel less confusing. Your definition of "friends" can also change depending on who the person is.
You might want to be friends with your ex in the sense that you're on good terms and want the best for each other, but maybe you don't want to talk about other people that you're dating with her. It's up to you what boundaries you want with her.
In your opinion, what do friends do? Do they talk on the phone or text? Do they hang out in person? Do they hold hands, or hug? Do they talk about other people they are dating or interested in with each other? What else is important to you to have in a friend?
This article might help you out, and it also talks about how important friendship is.
Why Does Friendship Matter to a Sex Ed Organization?