Eager to support the Macmillan Cancer Support campaign, Megan raised nearly £500 before her month of abstinence even started on Monday.
Proud mum Emma Mcnamara said it all started when Megan saw an advert for the Macmillan fundraising campaign.
She added: “I lost my mum to cancer before she was born and she said she would like to take part in memory of her nan.
“She said as she obviously doesn’t drink, she has decided to give up sweets, cakes and biscuits for October and raise money for Macmillan.
“This was all her own idea and so far she has raised nearly £500 through friends and my Facebook page. It’s such a humble thing to do and I’m so proud of her.”
Megan, of Canterbury Road, Worthing, has even told teachers at Orchards Junior School she will have to wait for the sweetie milkshake prize she won for good behaviour.
Emma explained: “She was due to have it in October but she doesn’t want to cheat, bless her, so she has told her school she will have to wait until November.”