There is no unitary viewpoint on contacting the present partner and/or the victim. The (lesbian) woman might still be with her partner or already be in another partnership. Sometimes partnerships contain more than two people.
There are some serious reasons to address the victim/partner:
Contacting the partner, some deliberations have to be taken into account:
Nevertheless, the participant needs to agree to this modality. If it is a condition of participation and the participant does not agree, a decision has to be taken: exclusion versus successful participation. Risk markers might be helpful to evaluate the outcome of the participation.