I do think you should know where the money is going. I was just picturing the the conversation that would be going on in a JWs head. As you pointed out if you are not a JW there's no trust and everything you do is suspect.
They do preach that the wife should be even more obedient to the husband to win him over. Maybe you could use that to get the the elders to back you up. It might be worth a shot. Use the sneaking around to make them feel guilty.
It’s eye opening to see the other side of the conversation for a change. Makes me wonder what the truth was behind all those evil husband stories I used to hear when I was in. To think I actually believed that being a dub made for better families even when one was an unbeliever.
The birthday comment was more wishful thinking.