Need a last character
congratulation 
“婷” &amp; “婧” are both 女部英韻, so, the third one, i would suggest:
婛 (u+5a5b)
http://humanum.arts.cuhk.edu.hk/Lexis/lexi-mf/search.php?word=婛
娙 (u+5a19)
http://humanum.arts.cuhk.edu.hk/Lexis/lexi-mf/search.php?word=娙
婈 (u+5a48)
http://humanum.arts.cuhk.edu.hk/Lexis/lexi-mf/search.php?word=婈
姈 (u+59c8)
http://humanum.arts.cuhk.edu.hk/Lexis/lexi-mf/search.php?word=姈
娉 (u+5a09)
http://humanum.arts.cuhk.edu.hk/Lexis/lexi-mf/search.php?word=娉
have fun :)