Hmmm, I thought I might join in just a little bit here.

I've had three skull fractures, and while they all occurred as the result of a single automobile accident, not a bicycle accident, I figure I've used up my luck, brain-wise, and prefer not to take any more chances. I already ride a bike, so not wearing a helmet does nothing special to improve my health.

While I appreciate that people have different opinions about wearing the helmet, the debate doesn't really address the OP's question. If the housemate is more likely to ride if she's wearing a helmet, then more power to her. In fact, it sounds as if not wearing a helmet will keep her off the bike. So what kind of hair suggestions can we come up with?

I don't have long hair, so I wish I could offer something specific to that. However, the hair thing is an issue with me, too. I have very fine hair that tends to go flat under a helmet. My solution was to find a good stylist, explain the situation to her, and let her give me a cut that is easy to fluff up after a ride. She "texturizes" it for body, and gave me a hair product (called "mud", I think) that seems to help an awful lot in terms of keeping it from going limp on me after a ride.

I style my hair in the morning, put the mud in, followed by hair spray. Then I ride around all day going to various places, wearing a helmet. When I get off the bike, I lightly fluff my hair and let it air dry. When it's dry, I comb it out and add a light pass with some hair spray again (if needed).

That's what works for me.