Kfir,

One thing to consider, smaller brake levers mean she will have LESS leverage when applying the brakes. She will have to squeeze harder to apply the same braking force. This could be important on a loaded touring bike riding down a mountain pass.

Some flat bar brake levers have an adjustable stop so you can reduce the gap between the handle bar and the brake lever for those riders who have short fingers. The trade off here is you will have less brake shoe travel. You can compensate for this by making sure the rims are true and minimizing brake shoe clearance.

My statements above assume the bike has rim brakes not disc brakes.

Good luck,

Tom Moritz