Welcome, MoNo 
I am assuming you are referring to search results as presented by Google.
Google is presenting a few links with payed ads somewhere in the list that look like ordinary links.
However, if you click them, Google redirects you to page like googleadservices or doubleclick before forwarding you further to the target page. These redirects won't work if the redirect host is on Pi-hole's blocklist.
Depending on your preferences, you have several options:
-
white-list those domains
(though that would somehow defy the very reason why you installed Pi-hole)
If you want to take that road, the forum topic How do I determine what domain an ad is coming from? has good insights on how to determine what sites to block. -
switch to an alternative search engine
(e.g. www.startpage.com which is a Google search proxy without allowing Google to track you)
Certainly a good step, worth a try, but your family may still not like this, as Google's sponsored ads are missing, and some of your family members might have grown accustomed to see them, as they are based on what Google and its partners already know about them. -
install a browser extension that reformats those links to take you directly to the target
(e.g. Google Search Link Fix would be such an extension (at Chrome webstore here).
This would probably imply you trust the extension's developer more than you trust Google, or you deem the risk of leaking data to Google as higher than leaking to a browser extension.
You could also go for a mix of any of those options - the choice is yours 