"This isn't Demi's show, but she sure is acting like it is," spills the insider. "She wants to make it a big, splashy affair and isn't listening to what anyone else thinks."
That includes Tallulah, 27, who "wants something quiet and simple in the backyard with just family and close friends," explains the insider. But Demi, 58, "insists that's just not good enough for her little girl."
Things may be especially tense between Tallulah and her mama after the 27-year-old posted an extremely candid post detailing her struggle with body dysmorphic disorder.
“I resented the resemblance as I believed wholly my 'masculine' face was the sole reason for my unlovability — FALSE!” she told her followers earlier this month, adding: "We all want to feel good, and confident but when it creeps into a deeper, spookier place where it begins to devour your essence bit by bit, ask for help."
At the time, the Ghost actress offered her full support to her daughter, writing: “Beautifully realized/Beautifully expressed/Beautiful to witness.”
While Tallulah knows that the Songbird star means well, "all the butting in this early in the game is driving her nuts," adds the insider. "She wants her mom involved, but certainly not to this extent!"