Brechje Mollerus' correct full names, origin, and baptism have not been identified with certainty. The first time we meet her with acceptible clarity as to her identity, is on 25 February 1687 in the Amsterdam Nieuwe Hervormde Kerk when she and her first husband, Petrus (Pieter) Hollegraeff/Hollegraaf baptize daughter Treintje.

At some point after this, but before 5 March 1691, the couple moves to Blokzijl in the Overijssel. We meet her seven times in total, and her name at those times is written variously as Bette Mullerus, Batte N., Brechje Mollereus, Battina Molinerus, Battina Moleneus, Battina Molerus, and Brechtje Molineus, as time progresses.

The last time we meet her is on 6 Nov. 1701, when she baptizes her last known child in Blockzijl. Based on the above, her full names may have been Elizabeth Gebrecht, or the reverse, and her surname had the root "Muller"/"Moller". The most common spelling of the latinised version of the name is Mollerus or Mullerus.

We do not have the details of her first marriage. It may very well be in Blokzijl, where her first hsuband, Pieter Hollegraeff, was born, but the marriage books of 1660-1684 have disappeared, and were possibly destroyed.