We could of had it all
If you do a web search for “could of“, you’ll find quite a few people searching for song lyrics. Examples of search terms include: 
“It could of been the champagne”
and “It could of been me.”
“We could of had it all” was a search for a song by Adele, called Rolling in the Deep.
And the line in question was, of course,
“We could HAVE had it all“.