Obviously you would go about it gently and if I had made it known to you that I am struggling then I think I would appreciate it.
Maybe not at the time though as quite possibly I had already been thinking along these lines and was very scared of what it could mean.
But an opinion from someone in the know is always going to be a touchy subject. Its a very hard call to make and depends on what the possible fallout could be if she takes your well meaning advise the wrong way.

Good luck