If she has bitten like this for no reason, then please do not have her around children. It only takes a fraction of a second for something to happen which would only put another big damper on our hobby. Frantic and upset parents. More people who will have "proof" of the dangers of owning reptiles. If you restrain her behind her head, I guarantee it will only make her mad and you will lose what trust she may have for you.
It isn't a risk I would take. Work with her for a long time until you can trust her with any one before you do this.