Ka cika wannan jumla: Bayan ta ƙaura zuwa County Limerick, O'Brien ta soma tallafa wa masana'antar lace da ke kasawa a Limerick. Ta yi hulɗa da masu sana'a na lace na gida, kuma ta ba su kayan inganci masu kyau da kuma zane-zanenta. Daga wannan ta shirya sayar da aikin, ta amfani da abokanta a Dublin da London. O'Brien ya kasance babban mutum a cikin kafuwar Kwamitin Kasuwanci don Inganta Lace na Irish, tare da goyon bayan Alan Cole na Ma'aikatar Kimiyya da Fasaha, Kensington ta Kudu da James Brenan RHA. Wannan kwamitin ya haifar da kafa makarantar horar da lace a Limerick a watan Mayu na 1889, kuma a cikin 1893 bisa ga bukatar kwamitin ta karɓi kulawar makarantar. Lokacin da iyalinta suka koma New Hall, kusa da Ennis, County Clare, a 1890. A cikin 1895, ta kafa Clare Embroidery, wanda aka gudanar daga gidanta. An taimaka mata a cikin wannan yunƙurin ta mai kula da yara na O'Briens, 'yar Scotland mai suna Mina Keppie, wanda ke da ikon horar da' yan mata 15 a lokaci guda. Kasuwancin ya koma tare da dangin zuwa Ballyalla a 1898, kuma a 1910 suna horar da 'yan mata 27 a lokaci guda. Dukkanin kamfanonin biyu sun baje kolin ayyukansu tare da zane-zane da zane-zane a cikin Ireland, Burtaniya, da Amurka daga shekarun 1890 zuwa 1920. Daga cikin wadannan nune-nunen akwai wadanda na Royal Dublin Society, da Arts and Crafts Society of Ireland, da duniya fairs a Chicago da kuma
St. Louis a 1893 da 1904 bi da bi lashe lambobin yabo da dama. A Lady Arran ta Windsor sayarwa a 1900, duka Sarauniya Victoria da gimbiya ta Wales sayi misalai na aikin su.