how can I get her to want to talk more?

This girl and I have texted a lot, she kinda likes me and has for a long time. WE have now fallen into the habit of texting for a bit and then taking a break throughout the day. She says she enjoys it cause she gets 'me' time and makes talking more fun. Yesterday was a bad day, she was tired and I was tired but we pushed through a texted most the day. Today we texted a few in the morning then I picked it back up around 10:30 and it lastest about an hour. This is how I ended the convo:

'Do you think its worth trying to talk? I honestly don't mind, I just don't want to be annoying.' - Me
'Maybe later when I'm not lazy' - Her
'hmm OK, I'm looking forward to it :). Should I wait for your text or just wait a few hours?' - Me
'Just text in a few hours' - Her

Did I make a mistake in how I ended that conversation? Its how most of them end up anyways though.

Does this girl live nearby? If so why can't you just see her in person? Then all this texting will not be necessary.

We are seperated by 200 or so miles unfortunately or this wouldn't be a problem at all.

So what is the point of all this? Unless of course the distance between you two will shortly become significantly less than 200 miles.

During college we will be within like 100 feet since we would be in dorms and if not that then at least a mile.