It is believed Andy Copland, 56, shot his daughter Maisie, four, and his ex-partner Julie Harrison before turning the gun on himself on 29 December.
Maisie and her mother, 40, were found with serious head injuries when police arrived at Church Hill in Aldershot.
The funerals for the pair are due to be held at Holy Trinity Church in Blackwater, Surrey, at 1100 GMT.
A private burial will follow the service.
Both Maisie and her father died at the scene, while Ms Harrison was taken to St George''s Hospital in Tooting, south London, where she died the following morning.
Hampshire Police said post-mortem tests on the three bodies showed they had all died from single gunshot wounds to the head.
Police believe the shootings took place as Maisie was dropped off for a visit to her father''s home.
When officers arrived at the scene, they made attempts to resuscitate the four-year-old but she was pronounced dead a short time later.
After the deaths it was revealed that Mr Copland had served two years in prison 23 years ago after he was convicted of harassing his former wife, Christine, threatening her with a crossbow and setting fire to her car.
An inquest into the deaths of the three family members has been opened and adjourned.