Sorting with Blank Cells

I have a list of people, their birthdates and their addresses. There's a column for each (see example below). Clearly, each person only has one birthdate, but several of them have several addresses (vacation homes, etc.). I only typed in their names once (i.e., there's a blank value in the people and birthdate sections in the rows of extra addresses). If I sort the list alphabetically by people's name, the extra addresses end up lumped together by themselves. Is there a way to link the rows that only contain extra addresses to their corresponding person entry so that they don't get lumped together?


Person | Birthdate | Address
Tom XXX YYY
Steve XXX YYY
Maria XXX YYY
XXX YYY
XXX YYY
Betty XXX YYY

If I sort by person, the "extraneous" lines get detached from the corresponding person.