Reports on this were pretty rampant around convention time in 2016, no denial were forthcoming.
It’s also no great secret that Slick Willy was a not infrequent golf partner of Trump, and both him/Hillary got pictured on more than one occasions with Trump, Trump also spoke glowingly about them before his run.
It’s must be said that the instincts were correct, Trump was the best general opponent she could’ve faced at the time (Kasich, Rubio, Cruz all lead in H2H polling pretty consistently, even Jeb! got a slight edge), however, he also failed to influence his wife to focus more on the low income white working class (there were multiple reports in Politico and similar outlets throughout the year that he felt they didn’t emphasize the economy enough in their campaign messaging), so in the end Trump ended up being the worst she could’ve faced. Not hard to imagine the Blue Wall holding if a dyed in the wool cookie cutter Republican like Rubio has been the nominee, or a known Tea Partier, hard right welfare slashing ideologue like Cruz.