In a nutshell, I think what you’re asking is: “Is it okay if the wife handles the finances even if Laura Doyle disagrees?” That may sound cynical, but I would like to stress how important it is to realize that this book, “The Empowered Wife,” is a secular source and certainly not Torah miSinai. While it may contain some good ideas, they are applicable only in certain situations with certain types of personalities. Treating this book — or any similar one — as an infallible guide for life is very wrong.
Your question highlights some of the misconceptions that people have with regard to marriage and shalom bayis guidance, and why it’s so important for people not to apply general statements to specific circumstances without getting expert, objective advice. Certainly when we find ideas from secular sources that seem useful, we need to be very cautious in applying them.
Only the Torah applies to all Yidden at all times, and only Hashem really cares whether our marriages succeed. One can find advice on shalom bayis in all kinds of places these days, and it’s crucial to ensure that any ideas we adopt are aligned with Torah ideas and ideals only. Before consulting a secular source, you should always ask the advice of someone you trust, who has a proper Torah hashkafah. Even when it comes to Jewish magazines and books, people should exercise their judgment and not interpret things literally or assume that advice that is good for one couple will necessarily be useful for another.
Another pitfall that comes with having a plethora of available advice is seeing problems where none exist. What in one person is a sign of a serious problem, could be in another person, nothing to be concerned about at all. For people who are naturally of a nervous disposition, reading about all the things to be aware of in married life can make them scared of getting married in the first place. Of course people should read and listen to shiurim and be attuned to their specific situations, but at the same time, they should be aware that situations are very individual and that whenever a serious issue arises individualized guidance is almost always needed.
It's possible that your sister, though she means well, doesn’t properly appreciate the dynamics of your relationship with your husband and doesn’t realize that advice that may be working well for her is not suited to your marriage. That’s assuming that the advice is working well for her, which I hope is the case. Doyle was writing from the perspective of a wife with (what we might call) a difficult husband and the way she chose to deal with things was perhaps helpful in that situation, although not everyone would necessarily agree.
I understand that sisters feel comfortable talking with each other and sharing issues that arise — that’s only natural. On the other hand, when it comes to seeking advice, someone so close isn’t always the best person to provide it. While not every problem demands a qualified therapist to solve it, many issues are better addressed by someone objective who won’t let their personal feelings color their input. Certainly one should not take a blanket statement from a non-Jewish source and apply it to any Jewish marriage.
With regard to the specifics of your question, I’m wondering why you use the expression “in charge of” when, from your description of things, it seems that you are not making the decisions or controlling the money you and your husband earn. If what you mean is being responsible for paying the bills and budgeting for expenses, with both you and your husband happy with the arrangement, I don’t see any problem in it whatsoever. If you’re naturally better at taking care of these things and your husband is grateful, then that’s wonderful.
You ask about the Torah perspective, and there is nothing in the Torah to suggest that a woman should withdraw entirely from the financial side of things and leave everything to her husband. Many great people have happily left all monetary activities in their wives’ hands and there’s nothing wrong with that at all.
The only thing to beware of — and it’s clear that you are aware of this — is not falling into a controlling pattern. As you note, according to the Torah the money you and your husband earn belongs to your husband and you may not withhold it from him even if you have doubts about what he might do with it. In exceptional cases one would need specific Torah guidance before doing things differently.
That doesn’t mean that if your husband is considering making or has already made a certain purchase that you’re very unhappy with, you can’t say something. Of course you may — and should — express your feelings.
As with any area of dispute in a marriage, the way in which you express yourself makes all the difference. Make sure to choose a relaxed time and place to discuss the issue, while speaking in a respectful tone of voice and taking care not to be accusatory or overly emotional. Keep a proper perspective.
As you note — which is very commendable — even when your husband buys something that you think was too expensive, at the end of the day he did go to the trouble of making the purchase. So, if you are troubled about it, you can certainly say so, but first stress how much you appreciate his concern for the family in taking the time to buy what was needed, and also that he isn’t stingy in providing for his family.
There will still probably be times when you feel challenged and upset about the way your husband spends money and you might not always see eye-to-eye even after a respectful discussion. That sounds just fine too — it’s likely to be a healthy sign of two people with different personalities who are trying their best to get along.
So, you ask, what can you do about that?
One way of looking at such expenses is that they are part of your “shalom bayis bill.” After all, swallowing $20 here and $50 there is still going to be a lot cheaper than paying for therapy... Obviously this doesn’t apply to seriously going beyond your budget on a consistent basis, but you could probably set a certain reasonable limit for “excess” spending per month and resolve not to say a word about it. If it’s a choice between controlling your husband’s spending and the hurt feelings of both of you, versus a little silence now and again and $100 per month, it’s clear which is the better option.
It can be very tempting to take a little book that presents a simple recipe for a happy marriage and follow its advice without ever questioning where the “good ideas” came from or whether they are really appropriate for Yidden trying to live as Hashem has commanded us. But it is only when we follow the Torah’s guidance that we will be’ezras Hashem have the siyatta diShmaya we need to build happy and harmonious homes where both husband and wife are comfortable in their roles and can express their individuality in the best possible way.