This singer has a biographical entry, in Irish, at www.ainm.ie. It contains one or two quotes in English. Here is one, attributed to Cyril Ó Céirín:

"Máire, a mezzo-soprano, combined what she had learned of sean-nós singing in the Gaeltachtaí with her training in classical music and was one of the few singers ever to do so with complete success."

And after Ní Scolaí moved to Galway, but before she got married, she came to the rescue of a theatrical production, and people sat up and took notice of her. She played the female lead in Diarmuid and Gráinne. Her Diarmuid was Micheál Mac Liammóir, who recalled:

"I was playing Diarmuid myself, Liam Ó Briain was Fionn (Finn McCool), and Máire Ní Scolaidhe, a lovely dark girl with astonishing golden eyes, was Gráinne. Of course, she wasn't up to a part that contained the stuff for a mature and lyrical tragedienne, but for sheer beauty and charm she was more than one could have hope for, and I have never ceased to be grateful for the hours of work she gave us, or for the grace of her movements."

Pádraig Ó Siadhail, writing in "Stair drámáoicht na Gaeilge 1900 - 1970" [History of Gaelic Drama 1900-1970], made two observations: Ní Scolaí replaced, in the role of Gráinne, a professional married actress whose husband, three weeks before the play opened, objected to the way that Micheál Mac Liammóir was kissing his wife in character. The actress is not identified in this biographical entry. In the same history, the author discloses that Ní Scolaí retired from the acting profession when she suspected that being an actress was doing damage to her singing voice.

August 28, 1927 in the Connacht Sentinel newspaper:
"Good acting, clear diction, beauty, grace, loveliness, she combined in a portrayal of rare merit. She reminds one forcibly of Miss Eileen Crowe in her early days at the Abbey Theatre. But we doubt if even that talented actress could bring anything better to the stage than the dignity and stateliness and ability of Miss Scully....Mr. Ernest Blythe, at the conclusion of the performance, highly praised Miss Scully. She was only a short time rehearsing the part, but she has the true artistic insight."