Broken bone - Metal pin disalignment

Hi,

My 4 yr old daughter recently had a fall and had a complete fracture. She needed surgery to put in 2 metal pins to hold her bones together while it heals. During the last medical checkup, the doctor mentioned that the x-ray showed that the bone had moved while being in the cast. He mentioned that since she is very young, her bone will mend okay and her arm will be good. However we are still concerned since the doc's assistants etc were very concerned.

Has anyone gone through such an experience?
What is the impact of the bone which is being held with pins in a cast moving ? Should I get a second opinion ?
Any advice in this regard ( especially if any of you in this forum are orthopaedic surgeons ) will be very helpful.

Thank you,
Ann.