As well as linking to your WebForm from your website, you can also embed your WebForm directly within your website.
To do this, you can embed the WebForm in an iFrame. Your WebForm is a HTML document, and an iFrame allows one HTML document (your WebForm) be embedded in another (your website).
To generate the iFrame code script necessary to do this, simply click on the Embed in my website button, which can be found between the Copy From and Proof buttons, just above the designer.
Clicking on that button will display a popup, which will show you the iFrame code. It will look like the below screenshot.
This piece of code can be copied, and then shared with the person who is able to edit your website.
Note: You may need to adjust the height and width of the iFrame to suit your requirements. You can type in alternate width and height values if you wish.
This HTML code should be easy to place in one of your webpages, and then you can share that page of your website just like you normally would with your customers. This will give them peace of mind that the webform is hosted on a trusted source.