Please note the names as per their baptism entries in the heading, as confusion between these two cousins seems to persist.
The muddle is not being cleared up by secondary and tertiary sources using "Hilletje Magdalena" for both persons. Furthermore, they were married to Pretorius brothers:
Heiltje, 1744, daughter of Zacharias de Beer and Anna Pretorius, was married to Johannes Lodewyk Pretorius.
Hyltje Magdalena, 1748, daughter of Matthys de Beer and Marija van Eeden, was married to Gerhardus Petrus Pretorius, and later Gideon Brits, b6c10. Positive identification both with her parents and first husband is found in her mother's estate inventory at http://databases.tanap.net/mooc/main_article.cfm?id=MOOC8%2F14%2E23... . This is also currently explained on her profile overview.
I propose that the individuals' profile names be corrected, especially removing the "Magdalena" from Heiltje, 1744's profile. It may also be useful to add a warning note to the respective curator notes.