Well, at this point, time is no object. But after enough time snuggling Edie is likely to figure out how to arrange for kissing to happen, given that Bella's head is in a position that would make it really awkward to try to lean over and peck her on the lips.
Okay, so she can--take her head off Bella's, and sort of nudge her head upward with her shoulder?
When they're at eye level and their faces are close together, it's possible she might freeze up a little.
Kiss?
If the kissing is equally incompetent on both sides maybe they won't even notice. Headtilt? People who are kissing in pictures usually have their heads at an angle, right?
And...you're supposed to move your lips while you're doing this, but not so much you slobber on the other person. And that is the extent to which her theoretical knowledge of the subject that can be trusted ends.
After enough snuggly kisses, Edie breaks away. "Um--I know we said we were going to do--things--but what things exactly were going to happen was not specifically defined and I did not specifically decide whether or not things possibly involving that lovely bed over there were a thing that I wanted to happen and I am definitely not opposed on a physical level but I need like five minutes to calm down to make this a deliberate choice and not just getting carried away."
"...Oh, I was sort of hoping to be carried away, but if you need to not be carried away sure, five minutes."
"I should have done this earlier. We can go back to kissing and getting carried away after." Inhale. Exhale. "Um--five minutes was an idiomatic usage, not an actual time limit or anything--okay," she says. "I pretty much knew already, I think, I just. Yeah." Kiss! Kissing is easier than trying to find words. Language is so limited.
Kissing: So much easier than language. There's a pun in here about tongues, but Edie is too preoccupied to find it.
Kissing certainly has gotten easier over the past while. Kisses kisses kisses. Carried-away wanderings of hands.
Wandering! This is the edge of a shirt. There's skin under there. This should be discovered empirically!
Bella has skin! All over her entire body. ...It's better than the alternative, anyway.
Oh, wait. Edie does have another piece of probably-reliable theoretical knowledge about kissing, and this is: you can put your mouth other places besides the other person's mouth. Like the jaw! Or the neck!