Hello,
I see that your daughter has a foot pain while walking and relieves on rest, this means it is mechanical nature of pain. By this I mean it will not be due to any
injury , so no swelling can be expected,
More commonly children who have
Flat foot have foot pain similar to the one your daughter is having.
A Flat Foot is a condition in which the arch of a normal foot is less or absent. this causes abnormal foot walking mechanics and causes foot pain.
To find whether she has flat foot or not, make her stand on the ground with both feet by side of each other and see the inner side of the foot, if only the ball of the great toe and heal touch the ground, then she has a normal arch of foot. If whole inner border of foot touches ground then she may have a flat foot,
Consult a orthopaedic foot surgeon in a non emergency basis,
I hope this was some help to you,
Dr Merchant