SCARY

So yesterday morning I was getting ready for work, I was in the bathroom, my daughter was on her bed (across from the bathroom) and my boyfriends dog (pittbull mix) was behind me.
I realized I heard the dog growling and looking at my daughter....I went into my daughters room to see if there was something she may have been teasing her with and the dog jumped up on my daughters bed and poked her really hard in the face with her nose, then continued to lunge at her again.
I grabbed the dog and pinned her down ( I was naked, had just gotten out of the shower) and held her there, yelled at her and made sure my daughter was ok. This pretty much ruined my entire day, I was scared, I know how much my boyfriend loves his dog, I love her too and my daughter would be devistated if we had to get rid of her (she and I lost our dog to cancer in november). All i could think about all day was what we were going to do when we got home, I was afraid my daughter would be ultra cautious of the dog and not want to be around her, my boyfriend said he was willing to give up the dog but I know that would kill him, he loves her alot.

Things went well when we got home, until this morning when my daughter went to feed the dog, then it almost happened again but was stopped because he and I were right there and the dog got pinned again, this time by him. Turns out she is becoming food agressive so now we have to work with the dog and my daughter so my daughter isn't seen as a threat to the food.
I am glad we figured it out but it still scares me. I have never had a dog that is that way, it's just strange to me.