Right, that is a tricky one, since it is not your job to "fix" things or try to manipulate your W.

Your W's priority is not the M as for the time being, she is "ok" with the status quo. If that were different, she would be doing things differently. She would be pursuing D. She would be working on the M. There would be "signs" that she is changing and therefore the sitch would change. When we talk about DBing being changing ourselves to change the sitch, what the LBS often does not see is, the WAS / MLCer is changing or has changed themselves, which changed the sitch and... the LBS then can not continue to operate in the same pattern they have been. That also happens if the WAS decides to work on the M.

Anyhow, as your W appears to not have a priority on the M (otherwise she would likely see the value of going on the date night and missing your D's afternoon games), she is resisting going because she thinks it's an "either/or" condition. IOW, either she goes with you to date night or she stays to watch D's games. In an either/or condition, she would have to see more value in going on date night. If it's not for working on the M, then perhaps it would be to have a great night partying and dancing and getting a tattoo or body piercing... She will do what motivates her more (or alternately avoid what she'd rather not do).

So you have a few choices:
+ figure out what would motivate her to go on date night (which would be the equivalent of you trying to "fix" her and make her happy)
+ figure out how to change Saturday from an either/or condition (which is still potentially fixing, yet with a more altruistic frame; a "win" for everyone)
+ let date night go, svck up the financial loss on the tickets (or sell them off to get your money back) and just enjoy the day
+ or you could even just go on "date night" by yourself

Which option would get you closer to your goals? Or what other options can you think of? Perhaps "date night" in the community where the games are and arrange a ride home for your D with another parent who will be at the game?