[wongarsu]

I honestly don't know if I would prefer CNLabelContactRelationYoungerCousinMothersSiblingsDaughterOrFathersSistersDaughter or CNLabelContactRelationBiǎoMèi (is unicode even allowed?). And I probably butchered that romanization and upset half the internet in the process.

[jerrre]

If unicode is allowed, you can also use the Chinese characters

[wongarsu]

Then about 80% of the world wouldn't know how to pronounce it.

A quick test in google would suggest that CNLabelContactRelationBiaoMei doesn't introduce too much ambiguity (first result for Biao Mei is still about the correct term), so even without unicode it might be fine.