Did you have logging enabled on Skype? If yes, then you can get the history of made calls. There's a program available (SkypeCallExporter) that exports it for you in an html file so you can print it. I sent the logs for all our calls in the last 1.5 years to show my husband and I talk every day. It was a total of 26 pages. Probably overkill, but oh well

The program is free, but if you need it and can't find it, let me know and I'll send it to you

Yahoo can keep a history of your chats too. I printed some chat logs from 5 yeard ago to show how we talked when we started out.
If you have the history turned off, then turn it on, now. It won't be much, but at least from now until you submit the application, you will have some records of you two talking.
Did you send each other any cards? Christmas cards, birthday cards? Include copies of those as well. I even included the cards my mother-in-law sent me.