Guy Hedger, 61, died in the early hours of 30 April after intruders reportedly broke into his home in Ashley, near Ringwood, and opened fire with a shotgun.
Helen Cooper, 40, from Poole, has been charged with assisting an offender.
She was remanded in custody by Poole magistrates earlier.
She is due to appear at Winchester Crown Court on 2 August.
Earlier this week the charity Crimestoppers put up a Â£10,000 reward for information that leads to the recovery of the firearm used and jewellery stolen during the raid.
Kevin Downton, 40, of Winterborne Stickland near Blandford, Jason Baccus, 41, and Scott Keeping, 44, both of Verney Close, Bournemouth, have been charged with murder and are due at Winchester Crown Court at a later date to enter pleas.
A 45-year-old-man from Poole and a 39-year-old Bournemouth man were arrested in May on suspicion of conspiracy to commit aggravated burglary and released while inquiries continued.
A woman has been charged as part of the investigation into the death of a businessman shot at his home in Dorset.