The Verdict: Not eligible
The marriage route only works if your spouse was French on your wedding day, so it is not open to you. Look at the spouse's residence permit and then naturalisation after five years in France.
Article 21-2 applies to a foreigner who marries a French national, and the administration reads that as French at the time of the marriage. A spouse who became French later does not open the route, even years on.
As the spouse of a French national you are entitled to a residence permit in France, and after three years of marriage to a ten-year resident card.
If your spouse naturalised while your children were minors living with them, those children may have become French with them.