Laura MacIntyre, 15, is said to have suffered serious burns, but no further information is currently available.
She was at the concert at the MEN Arena with friend Eilidh MacLeod, 14. She remains unaccounted for.
The pair were at the concert but hadn’t been in touch with relatives since the explosion at the Manchester Evening News Arena.
Updating the MSPs on the response to the atrocity at the Scottish Parliament, First Minister Nicola Sturgeon earlier confirmed the girls remained missing.
“Police Scotland are in contact with and offering support to the families of Laura MacIntyre and Eilidh MacLeod, the two young girls from Barra who are still unaccounted for having attended the concert last night,” Ms Sturgeon said.
“It is hard for anyone of us to imagine the anguish their families are going through right now. They are in our thoughts.”
Laura’s father Michael tweeted this morning: “Please...please retweet. Looking for my daughter and her friend. Laura Macintyre and Eilidh Macleod #manchesterattack”
He later told journalists: “It was Eilidh’s birthday present and the two of them are big fans of Ariana Grande.
“Laura was so happy to be going down there with her friend.
“It was Laura’s first concert. I was a bit hesitant about her going to a concert so far away but she seemed so happy.
“I’m waiting by the phone all day in case I hear any news.”
Eilidh’s aunt Margaret MacNeil posted on Facebook: “My niece and her friend were at the Ariana Grande concert tonight and there has been no contact since the explosion.
“Please let us find the girls safe and well.”
Angus MacNeil, the SNP candidate for Na h-Eileanan an Iar who knows both families, told The Scotsman that the Castlebay Community School pupils had travelled to Manchester for last night’s Ariana Grande concert with Laura’s mother.
It is believed that she stayed in a hotel near the concert venue while the girls attended the event, and has been trying to locate them in hospitals in Manchester without success.
Eilidh’s brother is traveling to Manchester from Glasgow to help with the search, Mr MacNeil said.
Mr MacNeil told the Press and Journal: “One of the girls, Laura, is a close friend of my daughter so it has been difficult.
“They were last heard from last night when they sent a message to say that Ariana was playing her final song.
“There is no answer on their phones this morning.
“It is heartbreaking and the island is in shock. Our prayers and thoughts go out to the families and all others affected by this awful tragedy.”
Western Isles Council told the BBC it was monitoring the situation. “We are closely monitoring events around Eilidh and Laura,” a spokesman said. “Our thoughts are with the families of the two girls.”
At least 22 people, including children, were killed in the explosion, with 59 people injured.
Ariana Grande has suspended her world tour following the attack.