A frugal single mum who made herself a millionaire shared her grocery shop tips
Serina Bird, 48, saves $5,200 per year by saving $100 a week on her groceries
She does 'Fridge Fridays' instead of ordering takeaway and clears out food
Serina also said you should do a 21-day menu plan instead of a seven-day to save
Serina made herself a millionaire by being thrifty and always picking good deals