iphone 4s - can't text non-iphone user

[sapphyre]

i have the latest and greatest ios&, i have turned on/off phone and wifi, reset network settings...i really dont want to reset phone...so tell me why i cant text a non-iphone user?  she has verizon as well.....also, this texting issue seems to be growing among iphone users, i have many employees with different providers all reporting same and different variations of a texting issue since ios7.

thank you