The event is set to take place inside the Fratton Road church and in the churchyard on May 2 from 10am to 4pm.
The 10-year-old is raising money for Wave105 Cash for Kids, British Heart Foundation, and QA Hospital by selling sweets, pocket money toys, and homemade items.
So far, Grace has raised £500 which has been split between her charities as well as being used to purchase Christmas presents for the QA children's ward and sensory stimulation items for the hospital’s rehabilitation unit.
Grace’s mum Sarah said: ‘Grace is a child that sees people needing something and straight away will think of ways to help.
‘In the last month aside from the three main charities who she is raising funds for she has helped a church that is providing support for families in need and Ukrainian refugees by donating her old toys and clothes.
‘As a family we are really proud of Grace, when she started this in 2019 we did not realise how much this would grow.
‘Grace is continually looking for ways to support anyone who needs it and we are happy to support her in any way we can.’
The youngster was nominated for a Child of Britain Award and received a merit for her fundraising efforts, and has also been nominated for a Pride of Britain Award in the GMTV young fundraiser of the year category.
Sarah added: ‘It makes us all extremely happy and humbled that Grace thinks of others and were astounded to be told that Grace has been nominated for a Child of Britain Award for her charity work and although she did not win she received a certificate of merit.
‘Hearing from others that Grace is being recognised for her caring and compassionate self is exactly what a parent wants to be told.’
Grace now has her own website for sharing her progress and upcoming events.