Kitten issues help me?

hey people x i just wanted to say im not aloud a kitten :( im working on it anyone got any gud tips on how to persued my mummy.. we have a dog ........ he is so nice with animals. he doesnt stay inside in the day but sleeps inside near the door. but my mum thinks cats scratch the sofa? and please dont tell me off wi spelling and gramma its cos its slang and faster or i cant spell some words. at the minute i have 47.75 to pay for cat food and litter ect. my dad said if my mum said yes he would pay for the vet bills and the cat. help me persued her pleaseeee and i want a kitten and i will still love her when she is a cat or heee ..........xxxxxxxxxxxxxxxxx