Under these sections of Reg. Z, the definition indicates that they apply to any consumer loan secured by the consumer's principal dwelling.

we have a loan that where the daughter and mother will both sign the note. The daughter lives in the house, her mother owns the house.

Definition does not state that said consumer must own the house. I'm thinking these rules apply to this loan as well as Escrow if a first lien.... What are your thoughts?

That's how we treated a similar loan request that was a first lien.