I deworm mom within a few days of birth because she is susceptible to a "bloom". The kids...I personally don't worm them unless a fecal warrants it but I do know that some worm on a rotation so I'd guess at around 4 months if you go that route. The reason for not worming, just in case you were wondering, is that way I know what type of wormer to use depending on the results of the test. If the fecal comes back "clean", I do nothing because using womers without cause can lead to resistance. Congrats on the baby!
Just as another quick note, the type of wormer you use depends on what type of worm issue you enccounter (there are three different classes that are treating by different products--Elevan, maybe might jump in here to direct you to her info which is very well put together )