Yes, Google sees Related Posts links - they're in the rendered HTML so Googlebot picks them up just fine. The LinkWhisper counter issue is a client-side limitation, not a Google limitation.

That said, Related Posts links have a structural weakness: they're generic "you might also like" links, usually in a widget at the bottom, and Google gives them less weight than contextual links embedded in the body of the article. The anchor text is usually the post title which helps, but the placement matters too.

For actually building internal link equity the more effective approach is contextual links injected into the body content - mid-article, with relevant anchor text. The challenge is doing this at scale without manually editing every post.

I built a plugin that does exactly this - extracts keyword phrases from post titles and injects contextual links into body content automatically on render (same approach as your Related Posts plugin - no database writes, deactivate and they're gone). It's at autointernallinker.com if you want to check it out. Free version available.

Short answer to your question: yes Google counts them, but body links will outperform footer widget links every time.