Hi Marie - I'm sorry to hear your mom's in constant pain from crossover toes. I found an article in a journal for podiatrists that discusses several treatment options, including steroid therapy:.
The following article also lists several treatment options, including shoe modifications and orthotic devices.
Do you think any of these options could help? Perhaps you could go with your mom to see her physician and discuss what can be done, short of surgery, to give her some relief from the pain.