A reply to Smilingnage. When you said that you could reverse/block/stop a womans technique I assume you were refering to someone of your own grade. Aikido relies on biomechanics whether we like it or not so of course if you know what technique said female nage is going to apply then of course you can prevent it. Who couldn't we all could and if the nage was male we could block/reverse/stop his technique too. Everything we do in the dojo is contrived, from nage knowing which attack to expect to uke knowing which technique is going to be applied. That is why it is crucial, to me anyhow, that we all try to be sincere. Attack with intent forgetting about the technique just try to make contact with your partner. How many of us have landed with a thump after taking ukemi for the instructor the first time a technique is demonstrated? That for me is training everything is unexpected you don't know what is coming so you just attack with everything...........then the bump comes.
Perhaps smiling nage you might ask a female dohai to take part in an experiment with you. You attack, a sincere attack she will know about if it makes contact, and she in return will try to do any technique to the best of her abilities (with atemi if she feels it's required).I think that with good technique surprise and atemi (if required) you won't be able to stop what's happening regardless of nage's gender.