I made a hole in my gf's favorite bag. HELP!

Im in huge trouble yall. I made a hole in my gfs favorite bag and I dont know what to do! She loves that bag cause it was given to her by her late mother a few years back. Shes going to be so pissed and devastated if she finds that hole sooner or later. Thats the only bag she ever seems to use whenever and wherever she goes. She brought it on the first day we met in the social dating tour, the night we went camping and hiking, and even at the beach! I seriously am scared to bring this up to her. I just dont want her to panic or cry. I feel so guilty. How do I fix this? As much as possible, without her knowing.