It's actually mhoithigh mé. I heard it from Seán Ó hÉinirí, he pronounced it something like "woeekh'ee". In the transcript of Scéalta Chois Cladaigh by Séamas Ó Catháin it is, at least. Take a look at this: https://ancroiait.wordpress.com/category/scealta-chois-cladaigh/
That page uses both spellings - mhothaigh sé an páiste ag caoineadh and mhoithigh sé na mná ag caint are adjacent to each other.
I'm pretty sure it's the same word, just a variant spelling, and clearly in that speaker's dialect it has a slightly wider meaning than I indicated above.