My 11 year old daughter has strained her neck when she was playing. I need advice on how best to deal with this problem.

Wry neck. Your daughter may have developed torticollis or a wry neck. A cervical neck xray may be advisable. In the meantime have her lie flat in bed without a pillow when sleeping. Apply either ice packs or heat to neck. Ibuprofen for pain. Physical therapy can also be helpful.