Great!
I find magnesium very useful for pain, spasms, cramping.
Many find Morton's Epsom Lotion helpful. (magnesium sulfate)
I also use 100 % pure magnesium chloride, by Life-Flo.
Life-Flow magnesium chloride products:
http://www.life-flo.com/magnesium.html (These products can be found at lower prices with an internet search. This is simply the product line.)
Magnesium will also likely help her to relax and to sleep.
If trying topical magnesium, it may be helpful to massage this into her shoulders, as well as her neck?
In fact, I use a small amount on the back of my neck to help me to sleep at night.
mrsD has a magnesium thread:
http://neurotalk.psychcentral.com/thread1138.html
I am thrilled your daughter is off of gabapentin (since it was not helping) and am thrilled you are feeling hopeful!
Much Love to you and to your daughter.
DejaVu