Sophie Edwards,a mother of two from Balby, near Doncaster, died after paramedics were called to her home on the morning of December 25.
Her mother Kelly Edwards said the family had been left numb by the tragedy and were waiting for the results of tests to find out the cause of her death.
Sophie is survived by her son Tyler, 7 and her three year old daughter Renesmee.
Kelly said: “It’s a bit of a surreal situation we don’t know hat has happened – we won’t know for about two or three weeks we will have to wait and see what they find.
“If it’s something that we can make others aware of if it happens to someone else. we don’t know ourselves yet. Hopefully in a couple of weeks we will have some more answers.
"Her boyfriend rang me as the paramedics got there. She was taken to Doncaster Royal Infirmary.”
A Gofundme page has been set up by Sharon Edwards who said: “Sophie’s live was cut short on Christmas Day and she was 25 years of age. She had so much to look forward to and was able to celebrate Renesmee’s birthday just before Christmas.
"Christmas for the children wasn’t the same, she had stopped breathing and by time she was taken to hospital she was gone, she loved her kids more then life itself and everyone who knew Sophie knew she was a young vibrant amazing women, mother, sister and daughter.
“The family has been overwhelmed with messages and calls asking how they can pay their respect so I have set this page up to ask for a small donation as the children lives have been upside down, they not only have lost their mummy they will no longer be living in the house she made a home.
“Let’s make Sophie’s last and final wish come true and help her children get a holiday that she was going to plan in 2022.
“We want the kids to have something to look forward to as they didn’t get to celebrate Christmas and raise their spirits just a little.”
You can donate to the fundraiser for Tyler and Renesmee here.