During the first few years, Ash and Katie bonded so much that they were inseparable.  When Delia and Colleen's families visit Professor Oak's lab, Katie would make friends with any Pokemon in sight.  Her first encounter was a Sandshrew and then a Doduo, and so on.  Professor Oak began to notice that Katie was bonding with the Pokemon in sight and realize that she would someday make a good Pokemon trainer.
 
On Ash's 10th birthday, he qualified to be a Pokemon trainer.  When 4-year-old Katie heard the news, she said to her mother 'Mom, I wanna be a Pokemon trainer just like Ash'.  "You're a bit too young right now, honey.  Once you get old enough, you'll get to go on your own journey.  You'll follow in Ash's footsteps someday' said Colleen.  'I believe that I wanna follow his footsteps when I want to.' Katie implied.  'Well, your time will come soon enough.  Right now, let's go to your Ponyta riding lesson.  OK?' Colleen said as she held Katie's hand and left the house.  Later that night, she had dreams about being a Pokemon trainer just like her older cousin.  'If only I could be enough to be a trainer, I could really be in the world of Pokemon' she thought and then drifted off to sleep.  In her dreams she was in a forest where a bunch of Pokemon would welcome her to their land.  There, she would meet a Raichu, the ruler of them all.  He would then greet her with a bow and a dance.  'Thank you.  It's an honor to make your acquaintance.  I wanna know something: do you believe that I could be a Pokemon trainer like my cousin Ash?' said Katie with a grin.  Raichu nodded.  The ritual went on until the dream ended by her mother shouting 'Breakfast is ready!'. 
 
A couple of years later, Katie was riding her Ponyta when her mother got the call that would later change lives forever.  'Katie, Professor Oak is on the phone and he wants to speak with you.' said Colleen.  'OK, be down there in a minute.' replied Katie as she got off her saddle.  When she reached the phone, she was exhausted like a Pikachu doing too many jumping jacks.  'Hello, Professor Oak.  How are you?' Katie said.  'I'm fine, thank you.  Listen, I have some news for you:  Since you've been bonding with Pokemon from an early age, perhaps you would like to consider being a Pokemon trainer like your cousin Ash.  Do you think that would be a good opportunity?'  Professor Oak said.  'Well.........I've thought about becoming a Pokemon trainer and maybe I would go on the journey.  OK, I'll do it! I'll have to talk about it with my mother first.  Talk to you later at the lab!'  Katie replied.  'I'll be looking forward to seeing you when you come to get your first Pokemon.'  Professor Oak said before hanging up.  The next day, Katie went to Professor Oak's lab to get her first Pokemon.  One Pokemon she had her eye on was a Pidgey.  It turns out that she got what she wanted and then her Pokeballs and Pokedex.  Then, she waved goodbye to all her family and friends before setting off on her journey.  Katie hoped to catch up with Ash so she would follow him to becoming Pokemon masters together.