unable to use geom_text to alter position of source labels

[BelindaCannell]

Hi Brian
I have looked at issue #222, and your suggestions re geom_text to modify the position of the source labels. However, when I tried
g = plot_data(filename="isospace_plot_21_V4", plot_save_pdf=F, plot_save_png=F, mix,source,discr, return_obj=T)
g + geom_text(aes (label = source$source_names), position = position_nudge(x = 0.1, y = 0.1), size = 3, hjust = 0.5)
I got this error
Error in check_aesthetics():
! Aesthetics must be either length 1 or the same as the data (10): label

when I tried
g + geom_text(data= source.labels, aes (label = label), position = position_nudge(x = 0.1, y = 0.1), size = 3, hjust = 0.5)
I got this error
Error in fortify(data) : object 'source.labels' not found

Can you advise what I am doing wrong please.

KInd regards
Belinda