I highly recommend ordering a replacement naturalization certificate. You may need in in the future to renew your own passport, get social security, apply for certain jobs or sponsor somebody for immigration. This is a must have document.
Also, if you get RFE for your kids cases asking for your certificate, at least you'd be able to send a copy. Do you have a copy of lost certificate? You could include that while waiting for replacement.
Did you send actual green cards? Why? I would never do that unless requested explicitly.
You should also consider filing N-600 for your kids as soon as you get your certificate. Good luck!