Does your number display correctly if you call her?
The fact that you receive texts and other people can call you suggests it's not a fault with your number, but with her phone or network provider, a phone number is a unique subscriber number used to identify and route the message/call so if others can contact you via both text and phone call, but your partner cannot, it suggests the fault is her "end".
I would suggest calling her and checking with her whether or not your number displays correctly on her phone.
