The mother of a four-year-old girl killed when she was struck by a tipper truck paid tribute at the child’s funeral service to a “sweet princess” who “brightened up every corner of our world.”

About 800 people packed into Bath Abbey to pay tribute to Mitzi Rosanna Steady, one of four people killed on a steep hill in the village of Weston on the outskirts of the city.

Songs performed by the children’s choir Melody Makers of Bath Abbey included Do You Want to Build a Snowman? from Frozen, one of Mitzi’s favourite films. Her tiny powder blue coffin was decorated with her name and a cartoon-like image of a girl with blonde hair – like Mitzi’s.

Her mother, Emmajade Steady, read a tribute she had written to her “beautiful Mitzi”.

“I woke up this morning to the heartbreak of no you,” she said. “No one to want to just sit and cuddle as life went on at its own fast pace. No beautiful Mitzi by my side, wanting to be involved in everything. The centre of everything. How can all our moments together be gone? How can it be that there will be no more memories?”

She said Mitzi was “just becoming a young girl”. “So smart, so open and free. I want to come home to you throwing yourself at me again. I want to give you your special milk on your cereal and ask: ‘What shall we do today?’ You were such a confident child, so sure in the love that surrounded you. You had the most beautiful wonderful everything. Stubborn and kind, loving and determined. Vulnerable but so fearlessly giving. You were so vibrant and alive.”

Her voice breaking, she remembered the “lovely tents” she used to build with Mitzi and the games of “dogs/horses/babies” that the little girl used to play with her sister Mycha – and the “rough and tumble games” she enjoyed with her brother Eric. She recalled how Mitzi had looked forward to her first sleepover.

“We only had four years with you but they were the best years of our lives,” she said. “You were the light of our lives, the love that filled our souls. You were the sparkle in a dark night and the laughter ringing in our ears. You brightened up every corner of our world. I held you and you gave me peace, you gave me happiness and joy and so so much more. Not just to me but to everyone you knew. You were so smart, funny, stubborn, gleeful, just amazing.

“I want you here with me for ever. I want to share forever with you. We will go on and try to live better, fuller lives, and to share the joy, you gave to us with others. You taught us all so much about life and love and living in your short years my sweetest angel and I can’t believe that I will never get to hold you or sing with you, giggle with or comfort you.”

She concluded: “I hope with all my heart that you are safe in heaven my darling baby girl and that we will all join you one day and have many more happy memories. Goodnight and God bless, our sweet princess.”

The funeral service took place exactly two weeks after the truck carrying sand and gravel hit Mitzi, from Bath, and her grandmother, Margaret Rogers, who remains in a critical condition in Southmead hospital in Bristol.

It went on to collide with a number of other vehicles before overturning on to a Volvo at the bottom of the hill, killing the three men inside. They were Robert Parker, 59, from Cwmbran, electricity company director Philip Allen, 52 and taxi driver Stephen Vaughan, 34, both from Swansea.

Avon and Somerset police have arrested the driver Philip Potter, 19, on suspicion of causing death by dangerous driving and manslaughter by gross negligence. A 28-year-old man, believed to be Potter’s boss, was also arrested on suspicion of causing manslaughter by gross negligence. Both men have been released on police bail pending further inquiries.

In a statement issued through the police, Mitzi’s mother and father Andrew invited everyone “that knew her or have been touched by her short life in some way” to attend the funeral service.

Mourners were asked to donate to the road safety charity Brake through a JustGiving page in memory of Mitzi as an alternative to flowers. The page had already raised more than £15,000 by the time the funeral began. Writing on the page, Mitzi’s father said: “Our beloved Mitzi passed away aged 4 on the 9th February 2015 in a tragic accident on a dangerous road next to her brother and sister’s school.”

Later he added: “What an amazing response, we are very touched. Some of the messages written have been really lovely and reminded us to think of the other victims. When fundraising is complete we’ll ask Brake if there is anything specific they can do for the Weston community and/or Lansdown Lane.”

Readings at the funeral service included verses from Song of Solomon: “For now the winter is past, the rain is over and gone/ The flowers appear on the earth; the time of singing has come, and the voice of the turtle-dove is heard in our land.”

The final song was an instrumental version of Billy Joel’s Lullabye: “Someday we’ll all be gone but lullabies go on and on/They never die; that’s how you and I will be.”