Hi Deep G,
As a resident of the UK you are liable to Capital Gains Tax on the sale of overseas property, you can find more information here:
Selling overseas property
You are correct in stating that although gifts of cash are non taxable, any interest arising when the money is deposited in an adult's bank account should be declared to HMRC.
Please refer to the guidance below for information on money invested in a child's bank account.
Interest on savings for children