She and her husband of 55 years each won £1,000 in their People’s Postcode Lottery draw on July 15.
Two weeks later, they struck gold, winning a bumper prize of £30,000.
The couple from Essex, UK are now planning a ‘big memorial’ for their late son.
Mrs Slater said her neighbours in Canvey Island are helping her with the planning.
She said: ‘We’re going to have a big memorial for him. We want to celebrate him properly.
‘Lots of people are helping me to do it. It’s old Canvey and we are a really close-knit group.
‘I just want everyone to come and raise a glass for Steve.’
Recalling the moment she heard she was a winner, Mrs Slater said:
‘When I got the phone call for this, I’d told quite a few people that I’d won £1,000 and I thought “this is a wind-up, someone is winding me up!”
‘Nowhere in my imagination did I think I was going to be lucky enough to win £30,000.’
When asked how she planned to spend her winnings, the pensioner said she was hoping to treat her family with her daughter, daughter-in-law, five grandchildren and two great-grandchildren on her mind.
She said: ‘Obviously, I should think they’ll be getting a little bit.
‘My husband and I have been married for 55 years this year and we always love a holiday, so this one is going to be extra special.
‘We love cruising so it will be quite a nice long cruise.’