U.S.A p expire help?? can my baby still enter with out hle..?

ok.. long story short.. my 5 year old u.s.a p port expire in feb 2010, she is doing her first few years of school in Jamaica.. she has her (unconditional stamp in her U.S.A p port) for Jamaica. but she is to travel in a couple months back to the u.s for summer. the proses to renew her p port in Jamaica is so long and drawn out its unbelievable.. any ways am in the u.s so i cant get to do it right away, she is in my Moms care... so my question is.. if she leave to come to the u.s with the p port expired whats the worst to expected? she will be coming with my mother... am sure they cant tell her she is not allowed to enter.. but will it be a big problem? it will be so much easier to mail it in when she gets here.. is there any number are link where i cant get proper information?