One of the most intimidating people I know in aikido is a sempai of mine from my old dojo. Well under five feet, barely 100 pounds fully dressed, but a spirit two or three times that size. I want to be her when I grow up.
Short blond hair? Blows through you like a freight train? Yeah, I know her.
I think there's no question that to get equal treatment you'll have to be more aggressive. One of the first female managers I worked with (early '80s) was in a management meeting which consisted of a bunch of men and her. At a particularly contentious point in the meeting, the men suddenly called a bathroom break and disappeared into the men's room. She hopped to her feet and followed them in. They freaked, but she said, "No way you're working out some private agreement in front of the urinals. I'm not leaving until you do."
You probably don't need to invade the men's changing room, but maybe you need to put more of yourself into attacks and making sure your technique is effective when you're nage. The idea of talking to your sensei offline about what you need to do to be a useful uke for him is a good one. Telling your partner outright things like, "Stop holding back on that throw, I need practice taking the breakfall out of it" is good too.