Clan MacIver is also an armigerous clan, in its own right. It's very unlikely that the names MacIver and Campbell would have been used interchangeably. It is possible that her mother's maiden name was MacIver (or whatever spelling). Looking at her estimated birth dates, it's entirely possible that she was previously married to a MacIver, as the legal age for marriage at that time was still 12. She may have used MacIver as an alias, but also seems unlikely. In my opinion, further research would be called for to identify her parents.
Amy, Clan Campbell Team Leader