Erraid, who is the youngest athlete at CWG 2014 and Scotland's youngest ever competitor, won bronze in the women's 100 metres breaststroke Para-sport SB9 final in a time of 1 minute and 21.68 seconds at Tollcross International Swimming Centre.
The teenage para-sport swimmer's movement is restricted by a problem with one of her hip bones, according to "BBC".
"When she was four she could hardly walk. "So the pool was the only thing that kept her fit. She swam her first mile before she was six. She's been swimming ever since and she's just got better and better," her father Davies told "BBC Scotland".
"I just managed to stop crying but it was difficult. It was amazing, absolutely amazing. That's the only word to describe it," he added.
"Erraid, from Shetlands (Island) is two months younger than Australian Jenny Tyrell, who won a swimming gold at the Christchurch Games in New Zealand in 1974," "Daily Record" reported.
"I feel really, really happy to have won. The medal ceremony was really good. I didn't know I was the youngest-ever medal winner in the Commonwealth Games. That is amazing," Erraid was quoted as saying in the British media.
Erraid revealed that she had hidden the news of competing at CWG, from her school friends.
"I didn't know how I would get on but I just wanted to do my best and that is what I have done. My mum and dad are here and I gave my mum a hug afterwards. I will take my medal to school and show my friends. They didn't even know I was coming here today. I didn't know how to tell them." Erraid said.
Many on Twitter hailed Erraid's achievement. Here are some of the Tweets.
Think back to what you were doing at the age of 13 & the scale of Erraid Davies' achievement hits home. Inspirational lassie #Glasgow2014— Martyn McLaughlin (@MartynMcL) July 27, 2014
Well done to 13 year-old Erraid Davies winning bronze in the women's SB9 100m breaststroke. Youngest ever @thecgf athlete - incredible!— Glasgow 2014 (@Glasgow2014) July 27, 2014
Bronze for thirteen year old Erraid Davies in the Para-Sport 100m breaststroke. Hardly a dry eye in the house.. pic.twitter.com/Pc98OSsdsH— Richard Gordon (@RichardGordon48) July 27, 2014