If you tell us what your plans are having the 3 accounts but obviously sharing all the names in the same household, we can better tell you what we think...
If you just want each family member to have an account, ok... nothign wrong with that, but like everyone said, if 1 goes down, so will the rest.
If you want to have 3 completely different accounts, well... at this point you are already linked completely and it may cause trouble sooner. 1 account goes down, so will the other 2.