OP I just read your case study and it seems like you have only started your MMM journey, I don't know what else to call it really, a few months ago. I'll repeat that a, few months ago.
Repeat after me. Suffering = Reality - Expectations
It seems like you and your wife have lived a fancypants lifestyle longer than you have lived frugal ones. It also seems like you are ahead of your wife on this and expect her to be at your level at the drop of a hat. You need to give it more time to change habits that took years to develop.
I know exactly where you are. I was there there about four years ago. I was never spendy compared to my peers and family. However, I still spent a lot of money compared to everyone around here. After our first child, I jumped on the FIRE wagon and found ERE, then MMM. I too started charting a new course for our finance and spending without giving my wife a chance to catch up. I wanted to cut our food expenses, shopping, vacation, gift giving and get above a 50% savings rate overnight.
In reality to took me a year or two to cut my own expenses, going out to eat, coffee, commuting, shopping, gifts, cell phone, ect. I tried to force my wife to make similar changes but all it did was create a rift between us. She was dealing with two kids at the time and adjusting to being a SAHP. Until I started cooking did we finally get our food expenditures down. We also stopped wasting food, we still do but not nearly as much, basically I would cook but we would still go out and end up throwing a lot of leftovers out.
Eventually, she started cooking more by herself, started shopping at consignment stores, picked free or lower cost activities for the kids, let me switch her on a prepaid phone plan(Iphone on ATT $140/month down to $25/month for both of us), and significantly dropped spending on gifts to family and friends. She still buys more stuff that I would care for, go on more vacations than I want, and buys junk food(that I don't eat). So everything is not exactly where I would like them to be. But we went from 20% savings rate to about 45% while adding two kids with only a 15% increase in income.
Give her some time, show by example vs constantly blowing up on $10 party cups. It's not worth it. Focus on the war and let go of some battles. It seems like the both of you have fat to trim. Treat it as a marathon and not a sprint. What's the point of getting to finish line and reaching FIRE if you end up alone with no one to share it with?