Am I over thinking things about this girl?

Been dating this girl for over two months now and things have been up an down. Last time I saw her, things went really well I thought. She opened up to me more and asked if she could sleep over Wednesday night and Friday night. So I know she wants to see me.

So anyways, I sent her a snapchat of me making her favorite sandwich saying "If only you were here." She was at work so she didn't respond back to me for 3 hours which was expected. But when she did she just replied saying "YUM" taking a picture at work. I wouldn't be upset with the one worded response if I didn't notice that she posted a picture on her story being much more enthused around the same time.

I'm really confused because generally one worded responses are a bad sign. Question is why did she just give me a one word response if she acted interested in me the last time we hung out?
Am I over thinking things about this girl?
Add Opinion