Cheryl Morris, 52, started struggling to complete simple daily tasks and suffered confusion and dizzy spells.
She went to her doctor who said she was suffering from either depression or the menopause and sent her home.
Weeks later she collapsed and she was rushed to hospital where medics said she had suffered a stroke.
But her daughter Shereen Richmond was still not convinced and demanded a full body scan which revealed she had a "massive" brain tumour.
She had emergency surgery to remove most of the tennis ball-sized growth, which was borderline cancerous, and is now undergoing treatment to control her symptoms.
Mrs Richmond, 26, is now urging people to insist on a second opinion if they suspect a diagnosis could be wrong.
The mum-of-one, from Lower Broadheath, Worcs., said: "Back in late 2018, mum was struggling to do certain tasks like lifting a jar out of a cupboard.
"Her doctor put it down to the menopause or depression.
"I wasn't convinced. I got a call on Saturday, January 19 last year from mum saying she'd collapsed at home.
"An ambulance took us to Worcestershire Royal Hospital where a stroke was diagnosed.
"It was like they wanted to just put a plaster on and send her home, but I told them that my mum has not only had a stroke and there is something wrong.
"I was adamant there was something more sinister.
"A paramedic pleaded with the doctors for me and they ended up doing a scan.
"I think it took him to convince them.
"I pushed doctors for a full body scan at Worcestershire Hospital and a doctor told me there was a massive tumour on mum's brain. I collapsed on the floor when I heard.
"I had to break the news to her two days later when she regained consciousness."
On February 25 last year she underwent a 12 hour operation to remove most of the tumour at University Hospital Coventry and Warwickshire.
Mrs Richmond added: "She wrote us all letters to say goodbye, she had already spoken with her local vicar to discuss her funeral arrangements and her will was in place.
"We really were all prepared for the worst, but of course always hoping for the best.
"Mum's first words to me when she woke up were 'I love you' - I was so pleased she could remember me.
"When she went down to theatre she thought she wouldn't come back.
"I have no dad, no grandparents, no siblings, my mum is everything and to say goodbye just wasn't possible, so I simply said 'I love you, see you soon'.
"The tumour was the same sort of size as a tennis ball and it was attacked to the part of her brain that deals with memory and processes.
"It took up over a quarter of her brain.
"She might not have remembered all of us.
"The doctors refer to her as a medical miracle because of all the things they predicted.
"It was so bleak.
"Not all of the tumour could be removed and there is a possibility mum could become seriously ill.
"The tumour will grow back within five years but at least it's not a fast-growing aggressive tumour.
"My mum has been on one hell of a rollercoaster during her recovery, but I am very happy to say that we are getting there finally."
Ms Morris, who is divorced, moved in with Shereen for around seven months as she recovered.
She said: "After the operation, I had some of my darkest days. I thought about ending it as I thought 'well I'm going to die anyway, I might as well do it on my own terms'.
"But my grandson Artie, who is two, would always cheer me up and pull me back from the dark place."
The pair are now raising money for brain injury charity Headway Worcestershire, which supported Mrs Morris.
To make a donation click on https://uk.virginmoneygiving.com/fundraiser-display/showROFundraiserPage?userUrl=ShereenRichmond&pageUrl=1.