Assault causing Actual Bodily Harm is contrary to Section 47 of the Offences Against the Person Act of 1861.
It is an �either way� offence. That is, depending upon its seriousness, it can be dealt with either at the magistrates� court or the Crown Court. Magistrates have the initial say in where it is dealt with. Their guidelines to help them decide this say that it should be sent to the Crown Court if the victim is considered vulnerable. It could be argued that a 14 year old girl is vulnerable when being assaulted by her father.
If the magistrates decide to retain jurisdiction, their guidelines suggest a �starting point� (for a first time offender pleading Not Guilty) of custody. The domestic situation and the victim�s vulnerability will aggravate the offence, but your friend will receive credit if he pleads guilty at the earliest opportunity.
A solicitor may be able to persuade the magistrates to retain jurisdiction and may also be able to avoid a custodial sentence being passed if a guilty plea is entered.
My own view is that there is a strong likelihood of a suspended sentence being imposed, together with, perhaps some probation supervision or unpaid work, depending on the contents of a pre-sentence report (which will be called for).