"You can't even tell the difference between dreams and reality"
--> Yet you're forcing your daughter to fulfill your own dreams by proxy.
"Reality has it's walls"
--> Yeah it does, and you're one of them.
"You've built up skills and experience since you were little"
--> Ever hear about "transferable skills"?
Sense of rhythm, a feeling for musical structure, (probably other things) ... a lot of stuff she would have learned playing piano would be(come) great assets for her as a singer.
"The only path where you can truly be happy is the piano"
--> You're not even looking at your daughter, are you? Piano is what's making her miserable.
"A song you started on a whim can't even ..."
--> Wee~elll... I'm kinda with the mom on that one. Ten songs; each one written, recorded, produced and illustrated in only a day* ?
(* except for The Fish One, they worked 3 or 4 days on that, but still...)
There's simply no way they can create a quality product that way.