Upvote:2
This How to avoid getting a visa refusal when applying for a UK visitor visa? covers pretty much everything you need to consider in order to prepare a solid application.
Provide a cover letter with your wife’s application that explains your own circumstances. Personally I would not make any comparison between your previous lifestyle in the UK and your economic situation now. Focus instead on stating the compelling reasons why you will all return to Pakistan at the end of the trip and providing evidence of ties to support that.
If you plan to stay with your father, you should provide an invitation letter from him confirming that he will accommodate you and your family for the duration of your visit What should a sponsor tell the ECO? A copy of your father’s passport should be included.
Finally, your question mentions that “She has savings in her account and my brother has also sponsored her. So, proof of funding is not an issue.” If that means your brother is helping her financially with the costs of the trip because you are not in a position to do so, then I do see a potential issue. A husband sponsoring his wife is completely normal. A brother sponsoring a sister is also common. However, a British citizen who is accompanying his wife on a visit to the UK but who isn’t covering the shortfall between his wife’s savings and the costs of the trip could be a red flag, IMHO.