If you do not already have one, you need to make a contact for yourself in Contacts.
When you edit that contact, one of the options is to Add Field (it is way down at the bottom just above the Delete Contact button.
When you click Add Field, one of the options is to add Related People. You can then add all kinds of relationships...wife, husband, boyfriend, girlfriend, spouse, partner, mother, father, child, friend, assistant, etc.
After you have saved all your info in your contact, go to Settings > General > Siri and make sure that your contact is the one selected under My Info.
This way, when you say to Siri "call my wife", Siri will look at your contact to see who you have saved under the relationship field "wife".
You can also just ask her. For instance, say "Siri, call my husband" she will answer "I dont know who your husband is" tell her your husbands name as he appears in your contact list. She will ask if you want her to remember it. Say yes, and it is done. Same for your wife, son, daughter sister.. etc. As for your own info, you DO have to create a contact for yourself. In it, you can put your address too. This is how she knows where you are. And where 'home' is. You can also use phonetic spellings in all your contacts. (it is right under their real names). First and last names, this way she can pronounce them correctly. For instance my name is Tabi, she was pronouncing it tobby. I put the phonetic spelling under my name as (Tabby) and now she pronounces it correctly.