There are a number of resources about the Gilbreths on the web. Many are outdated or incomplete, and many move locations within a larger framework from time to time. A currently validated list of sites includes:
These two sites were created and maintained by David Ferguson for a number of years, but ceased being actively updated well over a decade ago. The free host that holds both sites (Tripod.com) appears to be safe, but in these late, unattended days the first site generates endless popup windows and ads in the manner of sites known for malware. Use caution, but they are worth at least one visit before they disappear.
The significant material from both sites has been added to the archives here.
“The Wiki” of course contains several entries related to the Gilbreth family and their interests. None is especially enlightening but all contain some material of interest. The link leads to a group entry; other searches may be of interest as well.