Yeah, it’s Who Better Than Me by Phil Collins with the Turk and Tarzan names changed but it covers just about any two closely aged siblings IMHO:

Miriam
You’re one of a kind, I can’t explain it.
You’re kind of cool, in a wonderful way.
Though you’re weird, you can make it.
And who better than me to teach you.
Who better then me to set you on your way. (Mhm)

This could take some hangin’ in there
Though with persuasion I can take you on up
Make you grow up, beside the others
And who better than me to lead you
Who better than me to take you all the way (Hey hey hey yeah)

Asher & Miriam
Struggling along for years and years

Miriam
Until I came along for you
Now its all comin’ together

Asher & Miriam
And together will see this through
You for me and me for you

Asher
I can learn, I can listen
I know there’s something
Deep inside but
I need assistance to go the distance

Miriam
And who better than me

Asher
To teach me

Miriam
Who better than me

Asher
To tell me all you know

Miriam
Who better than me

Asher
You reach me

Miriam
Who better than me

Asher & Miriam
To show them all we know!