I missed this thread.
I don’t think the character has been submitted to be included in the unicode.
The closest you could get is 𬽥
A while ago I also looked into what the character for ê was supposed to be originally. After comparing with other Sinitic languages derived from Middle Chinese, I think the original possessive in Middle Chinese 其 (kê), which became 嘅 (ge3) in Cantonese, 個 or 个 (ke) in Hakka, and 个 or 兮 (ê) in Taigi. 其 itself was probably pronounced the same and used interchangeably with 个, which was the original way to write 個.