Try on a test site.
In Joomla,
Install Flexi Content and enable it.
Install your image gallery plugin. Enable it.
In Flexi, create a new article TYPE (call it gallery).
In Fields, create a new text field (call it gallery) - Assign it to Gallery Type
Select Yes - Trigger Content Plugins
Select specific gallery plugin from list.
Save it.
In Items create new Gallery Type Item and save it.
Return to Items view, select the new item and this time edit it, the gallery field will be displayed...
At this point you need to enter the ID or name of the gallery images folder in the text field you created. (you may need to upload/create the gallery directory beforehand)
Publish the item Type to view the gallery. You'll need to play around with the gallery settings etc to get your desired effects.
The above is not definitive - but should get you started.