Suddenly Unable to send pic/video to one specific contact

[CallyB1]

Suddenly I am unable to send picture or video through Message to my daughter on my iPhone or iPad. We can text, she can send pics and video to me....what I send to her either stops sending during the transmission or I first get a "Delivered" message which then turns to the red " Not Delivered" message. I have tried deleting her from my contacts and redoing a new contact info for her, restarting my phone/iPad, etc. All my other contacts work fine. Totally frustrated! Any ideas out there? Very grateful for some help!