Quoting Kayleigh-louise Moran:" I know a few guys with it as a name and the male form Lee is so over-used and common around here, nearly everyone who's having a boy gives it to therm as a middle where I'm from. "
I know a girl who's middle name is spelled Lee so I honestly don't think it really matters how you spell it. I like it either way.
This is the way it is in my family:
Robert Lee(my grandpa)
Brian Lee(my dad)
Harrison Lee(my son)
I was going to spell my son's like mine, but my grandpa found out he had cancer right before my son was born so we decided to spell it like his. He died 1 month after my son was born so I was glad we did.