One idea could be that Baby Goku discovers a hidden power within himself while on an adventure with Gine. Maybe they encounter a new and strange enemy that forces Gine to teach Goku some unique skills passed down in their family.
Maybe Gine meets Goku during a time when he is facing a great internal struggle. She offers him the motherly love and guidance he never had growing up. This could lead to Goku having a new sense of purpose and inner peace, which in turn affects his relationships with his friends and family on Earth.
By showing Gine as a protective figure in Baby Goku's life. For example, she could save him from a minor danger, like a small wild animal attack. This would make Baby Goku look up to her more and strengthen their relationship.
One plot idea could be that Baby takes over Goku's body and tries to use his power to conquer the universe in a more subtle way. He might pretend to be Goku at first and manipulate his friends into doing his bidding without realizing it.
One plot idea could be that Bardock, in some way, gets to see the future Goku achieves. Maybe through a time - warp or a prophetic vision. Another could be a story where Baby Goku is sent on a special mission, and Bardock's spirit somehow guides him. For example, when facing a really tough enemy, Baby Goku hears Bardock's voice in his head giving him advice on how to fight.
Well, a great plot could be that in his baby state, Goku attracts the attention of an old enemy who wants to take advantage of his weakened state. His friends then have to protect him at all costs. Also, there could be a plot where baby Goku discovers new powers that are unique to his baby form, like the ability to communicate with animals in a special way.
With Gine, her character can be developed by exploring her feelings towards Goku. She could be shown as a loving and proud mother, but also with a sense of sadness for all the years she missed with him. Her interactions with Goku could bring out her more maternal instincts, and she might start to see Goku as a symbol of hope for the Saiyan race.
One possible plot could be that Bardock and Gine somehow travel through time or dimensions to meet Goku on Earth. They could be shocked to see how strong and kind - hearted Goku has become, despite not growing up on Planet Vegeta. Goku, in turn, would be amazed to meet his parents and learn more about his Saiyan heritage from them.
In the fanfiction, perhaps Kid Goku is on a journey to find stronger opponents to train with. He comes across Gine who is in a difficult situation, like being chased by some bad guys. Goku jumps in to save her. After that, Gine is so grateful that she decides to cook for Goku. As they sit down to eat, they start to exchange their life experiences. Goku is amazed by Gine's gentle nature, and Gine is impressed by Goku's courage and strength.
One idea could be that Goku and Goku Black are forced to team up against an even greater threat from another universe. They start to understand each other's fighting styles during the battle and gradually develop a grudging respect for one another.
In some versions, the female Goku could be part of a prophecy. The two Gokus meet, and at first, there is some confusion and misunderstanding. But as they get to know each other, they discover that they are key to fulfilling the prophecy. They combine their powers and defeat an ancient evil that was threatening both of their worlds.