I am a member of Ancestry.com and do alot of research for family history. I also have a program on my computer called legacy. You can get it for free. Or the upgraded verson for a small fee. On Legacy they have listings for all marriages and children from those marriages. They also have the step children and inlaws and it goes just about anywhere you wish. In your case though, only you know how your children will react to their family history. If you were doing it just for you I would say enter both husbands and all children. There are no rules. I will have some free time this winter if I can be of any help doing research please ask. You can email me and I will let you know the info I need from you to do the research. It's amazing the info available at Ancestry.com. and other websites now available.
Marie