Since some people genuinely questioned about the correct age of Rukmini during her marriage & whether she was forcefully abducted. Her age was 16 as per Harivamsa. Her mature figure shows she wasnt a pre pubescent child.
Regarding her abduction, it is Rukmini who urged krishna to take her away & sent her family priest to pass on her letter to krishna. She was devoted to vishnu from her childhood & had mentally accepted Him as her husband even before she met Him. Krishna obliged to her wishes.