Should I 25M ask her 22F out on her last day of work ?

I 25M frequent our local ice-cream shop because they sell my absolute favorite flavor, and the girl 22F that works there is very nice to me and I sort of have a crush on her. This week she told me its her last week of work, and if I come to the shop on her last day, she will give me a free ice cream. I kind of like her, and was wondering if its a good time to be asking her out ?