As a girl I am lucky enough to have about 5 regular female training partners at my gym. From white to purple belt. Training with guys is great, they tend to slow down a lot more than girls (especially the upper belts) and let you work, practice moves slowly you have never tried before, etc. They go easier on me (most of the time) because going hard just isn't beneficial for either of us.

It does suck only having three training partners around my size and weight to train with (only one is a girl). That means we both only get to go hard very rarely. Usually it's me going 80% against a guy going 30% who is twice my weight. Nothing like competing in my weight class at a tournament. However, I learn a lot just from watching the other girls roll and training with them. They have learned a lot of stuff that works great against partners larger than them. Our purple belt is tiny but she absolutely kicks ass. She can tap most white and blue belts. I learn tons from her and she is a big reason why I'd never leave my gym. If she left I would follow her.

My suggestion if you are hoping for more girls to join up: be a rock. Be there all the time. My purple belt joined and for years was the only female in the gym. But eventually a new girl tried it and her being there made it more comfortable. They became friends and she trained regularly, now she has been there for a years. Than another girl joined and became friends with both of them, etc, etc.

The trick is sticking around and attracting other girls to stay. Otherwise a more shy girl might give up or switch to a different gym with more girls. Now that we have a good pool of girls we have a women's only class and we get new girls in all the time. They don't tend to stick around too often, but I imagine we get a lot more interest from girls joining than other gyms. Especially girls who have never trained before.