My husband often comes home late. Should the children and I wait for him to pray in congregation, or pray early in the prayer time?

Both are good; what matters is not waiting until the prayer time is nearly over. Praying early in its time has its merit, and praying in congregation has its merit too. If your husband usually arrives shortly after the azan, waiting to pray with him is a reasonable choice. If he comes home much later, pray first with the children. You can lead your daughters, or a son who has reached the age of discernment (mumaiyiz) and recites well can lead the family. Agree on a shared rule, for example: ‘If Abang isn't home fifteen minutes after the azan, we'll start first.’ A clear rule avoids feeling torn every evening. See congregational prayer guide.