simple answer is yes, she can appeal. Speak to the solicitor who represented her at magistrates.
However, most appeals are only successful if there is provable (still beyond all reasonable doubt) evidence that has either since come to light or can since be disproved.
I know she is your friend, but to be found guilty of anything nowadays is fairly difficult. If her injuries are bad, what went wrong? What damning evidence convicted her? If it was her word against the prosecution, then that is rarely proved beyond all resonable doubt. There must be some (more than likely independant) evidence she needs to challenge.