Hi ased444 Saikd,
The gifting of the properties to your children will mean that you may be liable to capital gains tax when you gift the property to your child.
You willl find a capital gains tax calculator here:
Tax when you sell property
If there is tax to pay, you need to report it within 60 days of the completion date.
At the end of the calculator is the option to create a capital gains account.
You can use this accout to report and pay any capital gains tax due.
You only need to open one capital gains account.
When you log into the account, you can report any gains arising from the disposal of the second property.
Thank you.