EnglishFern, there is a recognised category of prosecutions for domestic abuse - see www.cps.gov.uk/legal/d_to_g/domestic_abuse_guidelines_for_prosecutors/ - although it is recognised that tends to be a compendium of offences within a domestic context. There is a specific definition of domestic violence and abuse, described as:
"Any incident or pattern of incidents of controlling coercive or threatening behaviour, violence or abuse between those aged 16 or over who are or have been intimate partners or family members, regardless of gender or sexuality." This can encompass, but is not limited to, the following types of abuse:
psychological
physical
sexual
financial
emotional
Controlling behaviour is: a range of acts designed to make a person subordinate and/or dependant by isolating them from sources of support, exploiting their resources and capacities for personal gain, depriving them of the means needed for independence, resistance and escape and regulating their everyday behaviour.
Coercive behaviour is: an act or a pattern of acts of assaults, threats, humiliation and intimidation or other abuse that is used to harm, punish, or frighten their victim."
Interestingly, the section on evidence recognises precisely the sort of problems we have here:
"It is important that efforts aimed at gathering evidence to build a robust prosecution case are not focussed solely on the evidence of the complainants. The stronger the overall case, the less likely it is that it will be contested or, if it is, that the prosecution will need to call upon the complainant to give evidence. The starting point should be to build cases in which the prosecution does not need to rely on the victim. However, prosecutors should ensure that the views of the complainant are balanced with this approach, and the complainant is not overlooked during proceedings."
The trouble is that it's is very characteristic of domestic abuse, particularly non-physical abuse, that it all happens behind closed doors and so much of the evidence will come solely from a complainant who has been thoroughly gaslit so that she's not too sure of the truth anyway.