sweetie1986

I think your income alone and proofs that you can readily provide are good enough. I would suggest your getting the official tax transcripts of the last 3 yrs from the IRS website (link below).
 
https://www.irs.gov/individuals/get-transcript
 
Click on the right hand side where it says Get Transcript by Mail. Make sure you choose Return Transcript on the last screen. With the IRS official transcripts, you do not have to submit copies of W2's or any 1040 schedules.
 
Good luck.
 

Wow, $60k for a casino dealer?!  Sign me up!
 
Is there a reason why you do not want to include your spouse's income?

Just use your individual income with W-2. Your income is enough to sponsor your mom. you just need to fill out form I-864.

I will let the people with more knowledge correct me if am wrong.
 
The way you have it filled out is correct;
Part 6. Question 2. Is asking for the Sponsors (ONLY) income. In which case you put down your own. And since you are above the Poverty level it is fine.
 
Part 6 Question 19 You will put the total income shown on your tax transcripts 1040 as you have stated you did. 
 
Just out of curiosity when you file your taxes there is a line on the 1040 that shows your husband's total income and your total income separately. Does it reflect 60,000 for your total income? 

Because she satisfies the income requirements with just one income and no need for spouse's.

Your income shows on your W-2. I used to do it and it was fine.