Remove gallery from "latest galleries" frame (blog overview)

Hi!

I’m having two galleries set up only for specific friends or family-members which are having the actual URL.
These galleries aren’t password protected (don’t have to) and should be only available with the specific link (sent per email).

However, these galleries will get shown on the sideframe in my blog listing where you can choose between my blog entries (right side; [latest] “galleries”).

Is it possible to exclude these specific galleries or previews?
Or is there another simple way for such non-official galleries?

https://willigphotography.com/blog/
(i.e. “Lutz and Veikko” gallery is not supposed to be seen in that spot)

Thanks a lot!