Das Kind der Liebe

(literally "The child of love" or "Love Child") A German play by August von Kotzebue.

Published in 1780

At least four English adaptations of the play were published between 1798 and 1800 (see Wikipedia[1]). Among them are:

Lovers' Vows by Elizabeth Inchbald (1798 - the play famously rehearsed by Jane Austen's characters in the novel Emma).

The Inchbald version appears to have been performed a few times in South Africa. (See Lovers' Vows