Question: My husband has been a US citizen since birth, but I became a citizen in 2000, that is 5 years after my youngest one was born. Both my children were born in the US, one parent was a US citizen but the other became a citizen after they were born. Are they natural born citizens or not? It seems to me that they are more than native born citizens, since at this time both their parents are US citizens, but they may not measure up to natural born citizens. Am I right? If so, what would you call this 4th class of citizens?
Technically no, you and husband were NOT both citizens at time of birth.
You're correct. Your children are not natural born citizens, but they are native born ones.
“It seems to me that they are more than native born citizens, since at this time both their parents are US citizens, but they may not measure up to natural born citizens. Am I right?
No. The only way one can something more than a regular citizen is to be a natural born citizen, and, as implied by the title, whether you are natural born depends upon the conditions of your birth. It wouldn’t matter if your mother was naturalized sometime during your life. That would not affect how you were born.
That should be: “The only way one be can something more...”
Since your children were born in the US they are citizens by birth, "natural born citizens", yes.
"It seems to me that they are more than native born citizens, since at this time both their parents are US citizens, but they may not measure up to natural born citizens. Am I right? If so, what would you call this 4th class of citizens?"
There is no "more" than native born citizens. A "native born" and "natural born" citizen are the same thing. There is no 3rd class, let alone a 4th.
The US citizenship is their birthright, notwithstanding any foreign citizenship they may have acquired from you under the laws of your former country.