[to the [nth (generation)] generation]
0━┳
Robert William Phelps 1971 &2002 Melanie Clark 1973
┣━1━━
Ralph William Phelps 1998
┣━2━━
William Robert Phelps 2002
┗━3━━
Oliver Neil Phelps
[total][:] 3 后代 (5 [persons] [with] [spouses])