You should have exercise some patience to source for your personal money for trading rather than obtaining money from your wife to embark on a very risky adventure, trading is very risky and it's not advisable to obtain a loan for trading, meanwhile you can as well start with a small fund which you can afford to lose and trade with the fund until you are consistent in earning profit or if you had already done that already and willing to start with a borrowed $200, I think you should rather take 50% perhap if there is any losses the repayment will be easier to avoid unnecessary embrassment
Some people don't really know much about trading, they just hear from people that they are making money from trading, but they don't really care to do more research about it to know the risk that's in trading. It's kind of funny for a newbie that wants to borrow money from his wife to start thinking about profit already, if you want to start trading, you shouldn't be thinking about profit yet, you should be looking for the appropriate strategy which you will be using.
If am going to advice the OP, then I will ask him to return like $180 to his wife and then start trading with $20, after perfecting your trading, then you can source for your own money then start trading with it.