UPDATE: So how do you mitigate it?
There is plenty of advice in stuff up there that seems judgy or paranoid but actually engages some of these forms of risk.
- To make sure it is not a favoritism/pressure make sure there is no organizational power that can be contrived in an argument (or court) to show one is in executive authority over the other.
- To keep it from being a hostile work environment, take baby steps, and work on being aware of both how she reacts and how other folks in the lab react.
- To keep from being sued, be extra specially careful not to go anywhere near anything romantic until there is some strong and consistent-over-time trend toward acceptance and enough concrete evidence (not hearsay) to let you defend yourself in a court of law or even worse a brief university hearing in front of political sharks who would gut you for an ounce of push toward their next advancement.
- If it does get intimate, make sure you have both talked about and
agreed upon the method of "protection" ahead of time, so that pregnancy does not become a disruption. - Show enough consistent (and possibly expensive in terms of time or work) pursuit so that it is both widely obvious and any contenders can elect to join battle or forfeit in order to reduce human-level contenders.
- At some point, chat with a lawyer about liability and such. There might be free lawyers on campus that need volunteer work and could help you make sure you are not setting yourself on fire.
“Sonny, true love is the greatest thing in the world.” — Miracle Max, The princess bride