Re: Female uke
I've found that when my partner does the technique correctly, without trying to muscle their way through it, I won't get hurt, no matter how hard I go down. The problems only arise when someone does the technique incorrectly, and instead of stopping, tries to use force to compensate. As long as you're doing the technique correctly, your partner should be okay, irregardless of gender.
Also, in my experience, it doesn't do me any good to work with someone who's afraid of hurting me. If I don't experience the technique, not necessarily to the point of crippling pain, I have a very hard time learning. When I can't handle the discomfort, if I'm having a sensitive night, or a person does use muscle time and again, I will speak up and I will choose not to work a technique, or request gentler techniques, or whatever it takes for me to practice safely.
Just concentrate on the technique, and trust your partner to know their limits. As Mr. Stallard said, you can always ask what those limits are.