My girlfriend is sending me pics and my family gets them too?

Me and my family all have IPhones. My girlfriend sends me pics and my entire family can see them we all use my moms apple I'd but I turned off photo stream and they are still getting them

If sharing the same ID and sending imessages then thats designed to do that.

Since you are using the same Id it is syncing across all of the devices. To solve this get your own apple Id warning this will cause all app purchased on a different id to stop working properly on your device. Just delete them and repurchase them using your new Id