Several months ago, I worked alongside a girl (let's call her Sally) at my previous job. When we first met, she was already in a relationship, but as time went on, we both left the company. Since then, she went through a tough breakup with her boyfriend, thus preventing me from asking her out at that point in time.
A few months later, she invited me to her birthday celebration. About a week later, we hung out together for the first time, just the two of us. In our conversations, dating was a frequent topic, and we would openly share our thoughts and experiences. However, despite these discussions, we've never directly addressed the possibility of dating each other. There have been occasions where she'd make jokes about us getting married some day. And she has inquired about my dating life before, even stating that I'd be a catch.
I must admit that I'm really into her, but I'm unsure about how to approach asking her out. I've never asked out someone who started as a colleague or friend before. Are there specific things I should keep in mind or avoid when doing so? Any advice on this matter would be greatly appreciated.