Page Plus Cellular question

[rgG]

Ok, she can receive a picture in a text via iMessage over WiFi, at no charge.
If she receives a true MMS, not over iMessage, she will have to have cellular data turned on, on the iPhone. You cannot receive an MMS, from someone not sending an iMessage, without cellular data being on.
To see if data is turned on, on the phone, go into Settings>General>Network>Cellular Data and see if it is set to Off or On.

Edit: also, remember, she will have a charge for each sent message and each received message.