YOU SAID:

my sister is boring so I'd do this

INTO JAPANESE

私の妹は退屈なので、これを行うだろう

BACK INTO ENGLISH

Going to do this because my sister is boring

INTO JAPANESE

私の妹が退屈なのでこれをするつもり

BACK INTO ENGLISH

I am going to do this because my sister is bored

INTO JAPANESE

私は妹が退屈なのでこれをするつもりです

BACK INTO ENGLISH

I am going to do this because my sister is bored