Pre-ejaculate question.. need to know

I know this is a very typical question, and I kind of feel dumb for asking it. Mostly because I know it has been asked many times. But here it goes: The other night, my girlfriend and I were performing "outercourse" as it is commonly referred to as. I'm not going to get into details, but some of my pre-ejaculate got on her arm. She said something about it, but I just kind of laughed about it. Little did I know, she fingered herself with it. The pre-ejaculate was outside of my body for probably 30-45 seconds before she fingered herself. I know that pre-ejaculate is designed to flush out old sperm from my urethra. But I had not ejaculated in a couple days, and I drink water often, so I urinate quite frequently. So I think it should have been washed away prior to this incident. She is stressing out about it more than I believe the should. I would like a couple opinions about whether or not she could be pregnant. I do indeed know that there is always a chance, you don't need to inform me on that topic. I am fully aware. But I think in these circumstances, the chances of her being pregnant are very minimal. But I would still like to know what some other people think the chances are.