To the best of my knowledge, Suzanne, and I don't believe I'm wrong, the only nursemaid travelling on the 'Titanic' was Alice Cleaver, who attended the Allison children, Lorraine and Trevor. Famously, Lorraine Allison was the only child from first-class to perish, along with her parents, Hudson and Bess. The circumstances of Cleaver's rescue with baby Trevor have been picked over ad nauseum on the board over the past few years - I won't go into all that now but, suffice to say, she can't be the woman you're looking for.
It is possible that one of the female victims in either second-class or steerage had been working as a nursemaid, or was going to America to take up such a position, but I can't offer you any names. I've certainly never heard of such a woman, particularly one from Scotland, but that doesn't mean she didn't exist!