What was your and your wife’s citizenship at the time your children were born, and were they born in the United States? If you both were citizens and they were born in the US, there is no doubt that they are natural born. Anything else, there is doubt.
My children were both born on US soil. My wife is a US citizen, born in the US. I am not. Although, I am a citizen of a very friendly country. ;-) Can my children become president?