We have some four girls in their late teens and the same amount of boys. All of them are very skinny, have very thin wrists, and already due to their weight and lack of technique are easy to throw. BUT the girls attack softer, they are afraid of being hurt; for techniques ending with sankyo, nikkyo or something that could require a breakfall they always chose those partners of whom they are sure that they treat them gently. I always thought that I was of the gentle sort until one of these girls shrinked back with real terror from me when I bowed to her for some sankyo technique. I did not observe this behaviour in even one single of the boys.
We had a 4th kyu test at the dojo last night. It went well: the person testing showed good technique with good energy. This resulted in the person taking ukemi -- who was female -- flying around a bit, making solid contact with the mat, etc. Which was fine: she's a brown belt and the ukemi required was well within her ability.
But there was a female beginner watching the test who winced and cringed and muttered under her breath. To her credit, she didn't flee in terror, but she clearly has some work to do before she'll be comfortable in that role.