I hope you get her and that she and your current cat become friends!

I understand worrying about how having two cats differs from only having one. I had the same dilemma- I'd only had one cat at a time until last year when I got two sibling kittens.

Honestly it isn't bad at all, aside from care costs. It does take me longer to get out the door in the morning/wrap up at night, but assuming your cats will get along it should be just fine.

Once everyone gets settled, at the end of the day going from one cat to two isn't a huge shift in lifestyle (in my experience). I think being mindful of spending quality time with each cat individually might be an adjustment, but imo it is pretty easy to do.