Is she really ok with me doing this. Help:(?

I offered to get something for my crush that she wanted and when I told her it made her very happy saying that I'm sweet for doing that for her and I said I'll give it to her tomorrow. So tomorrow came and my dad had to use the car so I couldn't get her the thing she wanted until later. So I told her that I will have to reschedule and give it to her the next day, so she replies by telling my "it's all good" I know she understands but in my mind I feel like I disappointed her. Is there something I could do or say to make her feel happy.