Congrats man, you have found a connection and a real arrangement in the making. Lots of 'green flags' in your update.
It's ok you missed the signals, you were just being careful and not getting your hopes up. I remember being just as surprised when planning a second date having her ask 'Don't you want to fuck me?'.
Your best bet now that you are connected with her and past the meet and greet, building on a bit of what shack shared in his experience above as well, is focus on the fun with her and just be ready with your long term budget. PPM only discussions can feel so transactional and a SB may ask for the highest amount she can get thinking you only want to fuck her once and ghost her.
I've had better luck knowing what my monthly budget would be and you can do the same. Don't fall for giving the whole monthly amount right away - that can put weird pressure on even a great connection. Say you decide $2,000 is your monthly budget, and you feel comfortable sharing that with her, you're showing you are interested in the long term possibility of this working out. Then you discuss how many times a month you two will get together, say once a week, then a $500ppm would work each time you get together and get your freak on.
If your monthly budget is less or your availability is less because of the wife at home then what the SB wants - talk it out with her and unless you're being super cheap or she is looking for a really high monthly amount you didn't see coming, it will work itself out.
Good luck and thanks for sharing your experience here.
