The answer to your question is Yes. As long as you marry before or have a child before you can all apply for the conditional permanent residency.
If there is a marriage or child born after you obtain conditional permanent residency has been obtained then the new spouse and child can apply for the CPR.
You may be able to add your new spouse and children when filing the applications for the immigrant visa. You will have to provide proof of the marriage and birth, and each of you will have to file a separate application with the U.S. Consulate.