http://en.wikipedia.org/wiki/Bethóc

Bethóc ingen Maíl Coluim meic Cináeda was the eldest daughter of King Máel Coluim mac Cináeda, King of Scots, who had no known sons.
The strongest hereditary claim of succession to the Scottish throne therefore passed through Bethóc. Approximately 1000, Princess Bethóc married Crínán, Abbot of Dunkeld. The first son of this marriage was Donnchad I, who ascended to the throne of Scotland in 1034. Early writers have asserted that Máel Coluim also designated Donnchad as his successor under the rules of tanistry because there were other possible claimants to the throne.
It is possible that Bethóc had previously been married to Jarl Sigurd the Stout of Orkney, and to Findláech, the Mormaer of Moireabh.
She is not to be confused with Bethóc ingen Domnaill Bain meic Donnchada.