Hi Brett,
My 2 cts, everytime the frequency in communication has gone down during my online dating career, the relationship died. Yes some of them are very busy, my main current focus is a bit like your lady, slave job and hours, but she does office work so we QQ sometimes during the day, and she has an internet access at home so we QQ even more. Even when I am not online, she will wish me goodnight on QQ ... she makes it clear she is thinking about me, same here.
When excuses about busy schedule and work appear, be attentive. Compare to how things were before those excuses started arriving. The lack of affection when you met also has me wondering, they might be culturally reserved in public, and maybe you should have moved on her, but still. My ex grabbed my hand on our second date.
Why don't you just ask her how she feels about your relationship? If she loves you she will explain, if she doesn't, she might pretend to get upset.
Good luck!