Donald Horne Learmonth b 9 Mar 1856 married Rose Anna Manuel Houston b 1855 at Leith in 1885. They had children as follows
David Houston Learmonth b 1886, Stronsay, Orkney
Lizzie Rose Learmonth (known as Betty) b 1887 Stronsay, Orkney
Robert Learmonth b 1889 Stronsay, Orkney
Donald James Learmonth b 1890 Stronsay, Orkney
Lorenz Alexander Learmonth b 1892 Stronsay, Orkney
Janetta Anna Rose Learmonth b 1894 b Upper Scapa, Kirkwall
This confirms that Betty and Janetta were indeed sisters. As one other poster confirmed Netta emigrated to Boston in 1912. She married Fred Campbell. Not sure either regarding to comment on the following page to Alec Learmonth. Betty died in 1983 unmarried.
The family were living in Aberdeen at the time of the 1901 Census (168 Mid Stocket Road, St Machar, Aberdeen) but her father died in 1904 whilst trying to cross a fast flowing river in The Transvaal.