Johnston, 42, and Ringdahl, 31, want to have a humble wedding in a registry office or at the beach then go on a memory-making trip together. If Johnston isn't allowed to fly, they want to drive a Kombi van around the South Island.
"Marriage is first and foremost," Ringdahl said. "Then we want to go somewhere really cool with lots of water. Somewhere we can be completely on our own.
"I really want to get married on the beach," Johnston added. "I've always loved the beach. It's on my bucket list to learn to surf."
The romance started when Ringdahl lost her cat in an area near Johnston's Waltham home late last year. She posted about it online. After a bit of banter back and forth, the two met up in a cemetery where it was love at first sight.
"The cat was never found but true love was," Ringdahl said.
The couple got engaged early this year and put rings on hire purchase.
But their carefree "honeymoon period" didn't last long before Johnston developed stroke-like symptoms in June. She was disoriented, uncoordinated and had intensely painful headaches. After visiting an after hours clinic they immediately packed her into an ambulance off to Christchurch Hospital for an MRI scan.
There they discovered a tumour the size of a grapefruit in her brain. Surgeons split open Johnston's skull to remove the tumour but like "tendrils in a trellis" there was only so much they could take out without damaging her brain.
Susan Johnston has a massive brain tumour but wants to marry her fiancee Nikita Ringdahl in her last months. Photo / Martin Hunter
Johnston is now undergoing radiation, chemotherapy and taking up to 30 pills a day. She will then have a four-week break before starting a double dose of chemotherapy.
A large scar carves around Johnston's skull. She wasn't bothered until a large chunk of her hair fell out last week.
"I had to shave it all off. I was in tears all night. I had shaved it to a number 4 before but this is to the skin. I've got a massive bald patch around where they are radiating me and there's a massive scar from my ear to the top of my head then back down to my neck.
But Ringdahl was supportive: "She's obsessed with her hair but she's rocking the bald look."
Ringdahl has given up her work as a cleaner to care for Johnston full time. But it was hard going emotionally and financially. They thought it would only cost a few thousand to fulfil Johnston's last wishes, but with neither of them working it's out of reach by themselves.
"We cry every day. Every single day," Ringdahl said.
"I'm going through anticipatory grief, I'm grieving already because I know it's coming. I can't control it. It's so bad."
Ringdahl's cousin Nick Ringdahl has set up a Givealittle page to help the couple get married and send them on a honeymoon.
"I'd love if we could help these two tick some items off on her bucket list, make memories and most importantly make one of her dreams come true by becoming each other's wives," he wrote.
