I got the impression that
Ginko meets up with many females, some his age (and one even a Mushishi), but he deals with them in the way he generally deals with guys - maybe a little nicer, but that's about it. If they deserve his respect he gives it to them.
Here's a list of his encounters with the primary (or one of the primary) character in the story being a woman. Spanning vols 1 to 6.
Spoiler:
Vol 1 chap 4 - Mabuta no Hikari [animated] (loli, Sui)
Vol 2 chap 8 - Fude no Umi (girl in teens?, Tanyuu)
Vol 2 chap 10 - Wataboushi [I WISH THIS WAS ANIMATED] (married woman, Aki)
Vol 3 chap 11 - Sabi no Naki Koe (girl with good male friend, Shige)
Vol 3 chap 14 - Suzuri ni Sumu Shiro [animated] (suzuri-making woman, Tagane)
Vol 3 chap 15 - Sugame no Uo [animated] (female mushishi way older than him at this time, Nui)
Vol 4 chap 16 - Uromayu-tori (girl who runs a mushishi "mail service" using cocoons, Aya)*
Vol 4 chap 18 - Haru to Usobuku (woman with a younger brother who can see Mushi, Suzu)**
Vol 4 chap 19 - Kago no Naka [animated] (married woman, Setsu)
Vol 5 chap 21 - Okitsumiya (woman who can see Mushi, Mio)
Vol 5 chap 22 - Ganpukuganka (woman who travels and plays the pipa, Amane)***
Vol 5 chap 24 - Kagari no Kou (female mushishi, Yahagi)****
Vol 5 chap 25 - Akatsuki no Hebi (woman with son, Sayo)
Vol 6 chap 26 - Tenhen no Ito (girl who later is married, Fuki)
Vol 6 chap 27 - Saezurukai (young girl, Mina)
Vol 6 chap 29 - Yuki no Shita (young girl, Tae, with a good friend)
*As a Mushishi, Ginko has obviously visited her before. But she is not a woman yet.
** He stops in during winter, then stays for 10 days to teach Miharu about Mushi, and then comes back a year later. Suzu obviously worries a lot about Ginko.
*** She was born blind but with the aid of this Mushi she could see, but then it intensified and she could see throug things and through time. She found it troublesome and in the end asked Ginko to bury them so she became blind again. Ginko was of course shocked (you know him and his story about eyesight)... in the end he looks kind of sad.
**** She had this problem with a type of mushi in the village and Ginko told her not to burn the field they lived in, but she had no choice but to, in the end there's more problems and Ginko's back a year later to help sort things out.
I still haven't watched ep 15 yet but IMO that's probably a better... "candidate" - though onestly this show isn't meantto be taken apart for those kind of things. :P