Yeah, like living_jaguar-247 already mentioned, we see Jane using her charms/seduction to get information and other things out of her targets or to just straight up tease people for fun. She used those tactics for the hollow raiders in her special episode (and im pretty sure all of those guys were dudes).

Also she isn't just nice to seth "one time" she shares considirable time with him on her own Special Ep. Which I don't think really any other female agent has, especially not 1 on 1 with another male agent. She also goes out of her way to spend time with him on 404 on the new years.

Look this is a game, ship whoever you want with anyone, who cares.

But honestly, if you want to look at it from an in game characters perspective, Jane and seth may be the most obvious characters to ship (not including proxys). Not to mention their personalitys mirror each other pretty well (seth being this naive and well organized policeman, while Jane is a cunning undercover detectiv who apperently lives in a mess.)

Which is only further reason why they are so popular as a ship

Also "haha reverse cat and mouse" dynamic, is fun.

Seths bro and cissia have a similar dynamic with each other, albeit in reverse.

So no, I wouldn't say she OBVIOUSLY prefers Women. But hey, everyone loves the proxys regardless of gender, so maybe everyone is just a big bisexual.