We only have one Smart Phone in our family. Can I get my family members (wife, parents and kids) test reports on my registered number in MyReportPlz App

Yes Sir. 

Only thing it requires is, your Mobile number. Please ensure that while submitting samples to the pathology lab, you ask them to publish your wife, parent or kid report on your mobile number.

Once report is published, you will get instant sms notification on your mobile phone, the way you get for your report. And your family members reports will be available in your Mobile App.