I think the Witch just wants someone to unconditionally love her like a child should, hence why she wants Rapunzle as her daughter but is scared of letting her grow up and leave incase Rapunzel finds someone else to love and shes is trying to convince her to stay ("our little world is perfect") as the Witch is a very insecure person.
Thats if you want to think deep, although i do not think there is any hint of incest, but i prefer to just enjoy it!
Westend: Lion King,WWRY, Blood Brothers, Chitty Chitty Bang Bang, Woman In Black, Crazy For You, Wicked, Sweeney Todd, Much Ado About Nothing, A Chorus Line, Book Of Mormon, Merrily We Roll Along, Cripple of Inishmaan
Tours: Avenue Qx2, Grease, Sister Act,WWRY,Hairsprayx2, Never Forget, Blood Brothers x2, Singin' in the Rain, Legally Blonde,American Idiot x2, Phantom of the Opera, Beautiful Burnout, Our Countrys Good, The Ladykillers, Joseph,9-5, Rocky Horror, CATS
Regional: She Loves Me, Sweeney Todd, Kiss Me Kate, The Pajama Game, Barnum (Chichester) Metamorphosis (Lyric Hammersmith)Tristan and Yseult (Bristol Old Vic)
Tickets: Nevilles Island, Much Ado About Nothing