Is the second beneficiary/executor on a 1876 Irish will likely to be a son-in-law?

Question

Hi all,

I'm working on my McLean tree branches and trying to find more out about John MccLean who I know is the father of Daniel Mclean (1823-1896) through marriage records but otherwise I'm mostly estimating about.

. One likely will of a few with reasonable dates has a primary named Andrew M'clean and a secondary beneficiary named Samuel Ford. Would it be likely to name a son-in-law? http://www.willcalendars.nationalarchives.ie/search/cwa/details.jsp?id=1639534897