本人 1997 前和家人 ，連小女，已有居英權証書，但未取過。今天 小女已成年，可否現在去申請。 Kenneth 1133?

Something does not make sense here.

Officially, the proof of the right to abode for the U.K. is Certificate of Entitlement. But this document does not ordinarily issue for or in Hong Kong. And this certificate is not issued automatically.

On the other hand, the U.K. issues Certificate of Registration for certain Hong Kong residents for becoming British Citizen. This certificate is issued automatically upon becoming a British Citizen.

So the question here is what are you looking for - Certificate of Entitlement or Certificate of Registration?

Assuming Certificate of Registration, because one has been issued initially, you will need to apply for a replacement:

https://www.gov.uk/get-replacement-citizenship-certificate