This was fun to think about. It's a list of each crew member's family member and alternate versions of themselves who make an appearance. I'm sure I forgot some.

Crusher: son, husband (hologram), nana (deceased), fictitious future self, self from alternate timeline

Worf: adoptive mother, adoptive father, brother, stepbrother, mate, son, future son, fictitious future self, self from alternate timeline

Yar: sister, daughter of self from alternate timeline, self from alternate timeline

Troi: mother, father (dream apparition), absence of sister, fictitious future self, artificially-aged self, self from alternate timeline

Data: brother, grandpa, father, android replica of mother, time-shifted self (3 copies), fictitious future self, head of self from alternate timeline, self from alternate timeline

La Forge: father, mother (imposter), fictitious future self (with vision), self from alternate timeline (with vision)

Riker: father, alternate self, fictitious future self, fictitious hologram fantasy wife (deceased), fictitious future son (imposter), self from alternate timeline (dies)

Picard: mother (imaginary), brother, sister in law, nephew, memory of past self, de-aged self, vision of flute-playing self from a different life (including wife, son, and daughter), time-shifted self, less-ambitious self from a vision of an alternate timeline, fictitious future self, self from alternate timeline

Disguises: Mintakin Riker, Mintakin Troi, Vulcan Picard, Vulcan Data, Romulan Troi, Malcorian Riker