How do I create a space between two stills in order to add another at a latter date?

I have added a file to show you

what I am trying to do. E.g. place, maybe "a spacing" between two stills - that won't upset the current narration line and in order to drop another still when I get it from the person who is taking it for me in the next day or two. I am anxious to get this project done asap and if there is a way I sure would like to know of it. Thanking you in advance if you can help me.

Add a Gap Clip Opt-W. Make it whatever length you want.

What I do is play your playhead where you want the clip to be, select it in the Browser and use Q to make a connected clip. The gap clip gets filled in automatically. Then you can overwrite the gap clip if you want later (right-click the clip, choose Overwrite Primary Storyline.

Either way works.

I thought there had to be a way. Will do as you suggested. Many thanks

There's a third way to do it, which involves chewing gum, a small piece of aluminum foil, six inches of twine, and a paperclip. Oh wait, this isn't Avid, never mind...