After selecting the wallet hit the send coins button.
There will be a box titled Coin Control Features inside of this box , hit the inputs button. A new window will appear called Coin Control. In this window you have the option to use the tree mode or the list mode, I prefer tree mode, but decide yourself which you like the best.
You will see the total amount of coins held in the wallet with the amount of blocks held in the wallet in parenthesis. If you are using tree mode, hit the arrow to expand the view and display your wallet's blocks. You should see confirmations next to the block, and an aged coin should have around 30k or more confirmations.