I’ve managed to find Penelope Young, daughter of Penelope Thomson and John Young, in the 1861 Scotland census. In 1844 Penelope had married, for the second time, to William Meikleham, who became bankrupt in 1845. We know that William emigrated to Milwaukee, where he died in 1852 (the US Federal Census for 1850 has a ‘William Mickleham’, born in Scotland in about 1804, in Ward 2 of the local hospital).
We don’t know whether Penelope went to America with her husband and returned following his death, or whether they were estranged and she remained in Scotland. Either way, by 1861 she is living at 3 Duncan Street, in the parish of St.Mary’s in Edinburgh, with her daughter Joan Thomson, 25 and unmarried, from her first marriage to John Thomson; and her two sons from her second marriage, William junior, 15, and John, 14.
Penelope is described as a ‘fund holder’, though it’s unclear whether this is a legacy from her second husband, or funds inherited from the estates of her parents, or from that of Elizabeth Thomson – or a combination of these.
Incidentally, Ancestry has mis-transcribed the surname as ‘Meikleman’, but the original (accessible via Scotland’s People) has the correct spelling.