Not judged, just for fun. :)
If a rule for a nickname is given, that family member must have a nickname according to that rule; nicknames for other family members are allowed, but not required.
---
DH: FN is from mythology; MN is a filler name; NN comes from the first name.
DW: FN is a Biblical name; MN is a flower.
DD1: FN and MN are the same as DW's; NN can come from either name.
DS1: FN and MN are the same as DH's; NN is the middle name, or comes from the middle name.
DD2: FN is an uncommon Biblical name; MN is a nature name.
DD3: FN is the name of a saint; MN is a virtue name.
DS2: FN is a surname; MN is one syllable; NN is something unrelated to the name (e.g., Buddy).
DS3/DD4: FNs can be anything you want; MNs begin with the same letter; NNs rhyme.
DS4: FN is a trendy name; MN is a name that is often used as a nickname.