Again, you’re completely missing the point of what people are saying. Of course you can’t make someone do something they’re not ready to do.
Nobody is saying that by you speaking up, she’ll immediately wake up and realise she’s being abused and will file for divorce.
There’s a good chance you’ll be told to mind your own business, but the point is, you have nothing to lose by at least trying.
You don’t know for certain that she’s not unhappy and feels embarrassed by these messages, you’re just assuming because of her adding laughing emojis and posting about how happy she is on Facebook.
So, by speaking up, she will maybe realise she has some support, and this will make it easier for her to speak with you in confidence.
You might not get through right away, but you’d at least be planting a seed.
Keeping quiet is far more likely to ensure that she never wakes up for herself.