In 1996 one pound was 75 Pakistani rupees, £1=75 rupees,What was the rate of UK pounds in those days with relevance to Pakistani rupees ?
She inherited agricultural property in Pakistan from her father. She inherited property from her Spanish mother in Spain too.
In 1980s there were two main professions for well to do educated women in market mainly medicine and teaching.
Agriculture land back then was like 3000 rupees an acre,
So she must have had a lot of land she sold to bought properties in London.
In the east of London in 1996 a house was costing £50,000, meaning 37 lacs 50 thousands,
Agriculture land required to buy this house would have been 1250 acres
Highly unlikely but, possible, she just need to show proof that she bought the land with property sold.
But I doubt it, as an honest person would never take years and go through courts to show his true source of wealth.