Making a bequest for one's daughter in law

Q: My question to you is:

Notes to the question,

• I have two brothers and 1 sister (we in total are 4)

• Gold worth $2000.

• Written and signed on a piece of paper in presence of 2 witness (my wife's mom and I)

• No objections by brothers and sister.

Before my mom passed away, she wrote on a piece of paper that the gold worth $2000 should go to my wife when she dies (My wife's mother and I were the witness). None of my siblings knew about this and got to know after the death of my mother and haven't raised an objection. My mom gave my wife the gold because she made lot khidmat of her. What's the Islamic ruling on this? 

Not paying tax

Q: I have a trading firm in which we do billing for the government sectors for their purchases. We charge 1% for the work. Suppose if a person wants billing for 100000 then we charge 1000, which is insufficient for our firm. These people never pay us more than 1%. Most of the people do not even pay this 1%. Despite this, they give us 17% which we have to pay to the government as tax amount.

Because we cannot fulfill our expenses in that 1% which most of the people dont even pay, we utilize this 17% and dont pay to the government and provide the clients with fake receipts upon which there is no check and balance. So by doing this we get 17000 from 100000 billing. The clients just want the receipts and they have no problem whether we pay their tax to government or not. They just take the fake receipts and go. Every trader who runs firms like this, dont pay the tax and consume it. Even the clients think that these traders dont pay the tax but they have no problem with this.

Now I want to ask you that if we do not pay this tax amount and we provide people with fake receipts, is my earning totally haram? I have no other business option apart from this. We lie to customes also that your tax is paid by giving them the fake receipts. My heart is not satisfied from this earning but I dont have any other business option. Kindly guide me what should i do? Can i continue like this because everybody else who is running this business do the exact same thing. Clients dont give the commission and thats why we consume the tax amount as our earning.