I want to get rid of my sisters cat
Why do you want her cat gone?
I am growing too close to the cat and don't have time to look after it.
You are happy with the cat but yet want to get rid of it, but that makes no sense. You are not the one who decides what to do with your sister's pet. If you get rid of it your sister will be angry and sad because you acted so wrongly.
This cat is so cute but so annoying sometimes. I need more time for myself.
Are you joking around or serious? Your sister is the only one who can decide if she wants to keep or get rid of her pet. How would you feel if someone suggested you get rid of something you loved?