This is not permissible. You have to pray in the masjid and go back home to give her a hand. It is only few minutes that you spend in praying.

Usually when I return home from work its almost maghrib time and after staying sometime at home I leave for Masjid. However, my kids are really cranky at that time and my wife wants me to support her with house chores and kids and pray at home as she is pregnant too. So, is it permissible in this case to pray at home while helping wife and kids.