In those times, it was considered comical. Fast-forward half a century, and Nottingham Playhouse produces a version of the Madness of George III, where the part of Charles FitzRoy is played by a woman without an arm (left corner, red coat):

The character behind her, in green coat, is doctor Richard Warren, by the way; also played by a female actor.
On the other hand, theater has always been like that, when first all female parts used to be played by men, and then the tables turned somewhat.