I believe you.
My daughter sleeps with us too, they really seem to think co-sleeping is good for youngsters, and as with everything, with the good comes the bad! (Veg for example!) I'm sorry this has happened, but we've all (or at least, I know I have!) had little accidents at some point or an other. Usually when we're trying to do the 'right' thing, strangely enough! Try not to be too hard on youself (says she, who bumped her daughters head on the roof of the car, when she was really young, and I didn't stop crying about it for over two weeks!) your lovely daughter is fine, and she's certainly got a very loving and caring mum!