About a month ago I asked out a girl at my college (she's a senior), and she seemed legitimately interested when she said yes. I texted her a couple days later to see how her schedule was, and she said she was pretty much busy all through the week. The next week I gave her a call, and she said she'd likely not be available until school started, which at the time was 3 weeks away. I said, "Alright then, let's say we wait until then and we'll try again?" which she said would be fine.

That was that, and also the last time I contacted her. Well school officially started now (started last week), so I've been contemplating trying one final time. I don't think I did anything in particular to make her lose interest. I feel a few texts and a single phone call to discuss logistics wouldn't come off as creepy and/or desperate, so that can't be it. My only thought is, because I'm much older (I'm 30, she's 21), she may have felt pressured into saying yes and doesn't feel she can tell me directly that she's not interested.

Or could she just be legitimately too busy? She told me she's working three jobs. Those who know her (like my downstairs neighbors) have also told me this, so I have no reason to disbelieve it. Any advice?