Puting two images side by side using twenty eleven theme

I am trying to get two images side by side just using the visual editor screen – so I can show a client how she can do it easily herself.

But I can’t get it to work at all.

Here is the test page I have set up to illustrate the problem.

https://www.helenpakeman.co.uk/test-page-2/

The code for each of the inserted pictures is

[caption id="attachment_435" align="alignnone" width="225" caption="Helen Pakeman 'Cornish Avenue' 21cm x 15cm, linoprint"]<a href="https://www.helenpakeman.co.uk/wp-content/uploads/2011/10/Helen-Pakeman-2Cornish-Ave3-e1319710326148.jpg"><img class="size-full wp-image-435" title="Helen Pakeman 'Cornish Avenue'" src="https://www.helenpakeman.co.uk/wp-content/uploads/2011/10/Helen-Pakeman-2Cornish-Ave3-e1319710326148.jpg" alt="Helen Pakeman 'Cornish Avenue'" width="225" height="300" /></a>[/caption]

[caption id="attachment_433" align="alignnone" width="210" caption="Helen Pakeman base 'Cornish Avenue'"]<a href="https://www.helenpakeman.co.uk/wp-content/uploads/2011/10/Helen-Pakeman-base-Cornish3-e1319711568325.jpg"><img class="size-full wp-image-433 " title="Helen Pakeman base 'Cornish Avenue'" src="https://www.helenpakeman.co.uk/wp-content/uploads/2011/10/Helen-Pakeman-base-Cornish3-e1319711568325.jpg" alt="Helen Pakeman base 'Cornish Avenue'" width="210" height="210" /></a>[/caption]