Yay! A female Ultra! While we're on the subject, have there been any female Ultras in the show?
Warning this post contain spoilers for several Ultraman TV series.
Yes there have! While not as common as their male counterparts, there have been a few prominent Ladies from the Land of Light to show up in the series. Perhaps the most famous is Mother of Ultra who, as her name suggests, is the mother to Ultraman Taro and Aunt to Ultraseven, Ultraman Ace is her adopted son. She is the wife to Father of Ultra.
She serves the Space Garrison as a medic and her healing powers are second to none. It was she who rescued Dan Moroboshi and healed him back to full strength during the events of the Ultraman Leo TV series. She could even bring the dead back to life. It is later revealed that her true name is Marie. She also has taken on a human guise in the past, called The Lady in Green.
Most recently, she has appeared as a spokesmodel for the newly renovated Amu Plaza Hakata shopping center.
The second most famous female Ultra is Yullian from Ultraman 80.
Yullian is a Princess from the Land of Light who came to Earth to warn Ultraman 80 of an assassination plot against him. She ended up staying and taking on the human guise of Ryoko Hoshi, joining 80′s human form Takeshi Yamato in the defense force called UGM. Her human form was played by Sayoko Hagiwara, best known to Super Sentai fans as Rei Tachibana/Dyna Pink from 1983′s Kagaku Sentai Dynaman.
She was very much a fish out of water and new to Earth customs, relying on Yamato (a teacher in his human life) to show her the ways of humans and their culture. She was also forbidden to use her powers lest she be discovered for who she was, even though she could use some of them in her human form.
Eventually, she was forced to transform back into her true self to help Ultraman 80 when things were looking their worst.
Sure enough, this blew their cover and the pair had to leave Earth and return to the Land of Light after their final mission with UGM.
That’s really just scratching the surface. There were other female Ultras as well but these two are the most well known and prominent of their heroic sisterhood.
Thanks for the question!