This question already has an answer here:
My wife and I will be travelling to the UK together. My wife depends on me. In my application I completed the income part.
In my wife application:
In the part "planning to spend money" in the UK I will put 40% of my total cost of the trip. For example, I put GBP 3,000 in my trip cost. Now I will put for my wife GBP 1,200. Is this ok?
Secondly, in my wife's application I don't know what to put in "Spend money in each month" because she is dependent and I spend in my home monthly. I just give her pocket money or for purchasing some food items. Now what should I put in this field?