You are not legally allowed to use a gun to defend yourself or your family. Whatever you do use, you will have to prove that it was a random choice of normal items you had in the house at the time. You can't for instance have a baseball bat unless you can prove you regularly play baseball. You can't have a table or chair leg by your bed to use in self defence. If the assailant has a gun, the best you can do is try & get your family out of the house, but bare in mind they may be in danger outside too! You can use a chair or a kitchen knife but these have their limitations if there is more than one intruder & they are armed. Basically you have a choice, you can either be a victim, or you can be a criminal!
Possessing any object specifically for the purpose of self-defence, lethal or non-lethal, is a criminal offence (in Australia). There are many women, raped and/or murdered, who would have been liable to prosecution had they been carrying anything that might have saved them.