The image that Facebook uses is defined in tags called OG tags. If these are not present in your blogs, then the wrong image may get posted with your articles.

If you are using the Real Estate Voice plugin, it can automatically add these tags for you, go to the settings ->Facebook tab:

Check the box and save the changes.

Try and share another article - articles you have shared in the past will not be updated.

Still not sharing the right image?

Sometimes you may have another plugin that is overriding the image that gets used when sharing. One example of a plugin that does this is Yoast SEO. Yoast ofers a default image to share which can overwrite the share image. Look for any plugins like this and turn off that functionality. In Yoast, that setting is located here (Yoast->Social->Facebook):

Remove the image and save changes.

If you are not using a WordPress website, then you may need to ask your website provider about enabling OG tags on your website.