As previously mentioned the expiry dates on you PR cards are irrelevant. At this point your whole family is out of status and you can't sponsor your non-PR child until you are compliant with your RO. There is no guarantee your child will be granted a TRV or TRP if you apply for one. Even if you do your child may not qualify for free schooling or health care during those 2.5-3 years until they get PR.