We were thinking of renting bikes at FW. DW insists that DD7 wear a helmet. (Yes, it is something we all should do) Are helmets available at the bike barn?
Bike helmets are pretty inexpensive to buy. Plus you wouldn't have to worry about what someone else before you left in the helmet (lice?). A helmet needs to fit properly to be effective. Owning your own would allow you to adjust the fitting properly.
Your wife is one smart lady! I personally know 3 people who would be in very critical condition, maybe even dead, if they had not been wearing their helmets - one is my DH! They are all avid bikers (rallies, races, etc). My Dh was on a simple bike ride one morning here in our neighborhood, last week. A car cut him off and he hit a branch in the rode, causing his bike to come to an immediate stop - but not his body. He flip over the handle bars and hit the road with his head and shoulder. His helmet is gashed up and split in several places, and he has a level 3 AC tear in his shoulder. Who knows how bad it would be without his helmet!
OK, off my soap box. I'm glad you are researching helmet options before you go!!!