So far, female Super Saiyan is still unseen on "Dragon Ball" universe, but things might change in "Dragon Ball Super". The promotional video of the latest arc "Universal Survival" features a female that looks like a female Broly when transformed into the Saiyan form This Saiyan is rumored to be in Universe 11. Universe 7 might be having its own female Super Saiyan soon too if they are lucky to even exist in the future.
There are two candidates for being a female super Saiyan, Gohan's daughter Pan, and Vegeta's newborn child Bulla. But the focus right now is on the newborn Bulla, which makes its appearance on GT as a teenager. According to Comic Book, Bulla's first appearance on "Dragon Ball Super" is one of the weirdest births on Anime ever. And they're quite reasonable about it. Vegeta won't budge when he was invited to the Tournament of Power, so Whis got to interfere. Whis used his staff and voila! Bulla was born.
There are talks now on how Bulla will turn when she grows up. Vegeta got a Super Saiyan Son Trunks, so it is possible that Bulla will turn Super Saiyan just like her brother. It is also possible that since she's a female, Bulla will follow Bulma's path as a great scientist. She can even be the next CEO for the Capsule Corp. As seen on "Dragon Ball Super", Trunks wants to train with his new sibling and he's not that excited when Bulla turns out to be a girl.
Folks from IGN thinks that Bulla being a Super Saiyan will make an interesting dynamic between Bulla and Trunks. Sure Goten is already there to feather rivalry for Trunks, but sibling rivalry is quite interesting. As per Bulla VS. Pan, no one knows who will be much stronger. But if the hybrid theory of Saiyans is followed, Pan might be stronger given that she's 1/4 Saiyan and 3/4 human.