When I say in the equation, I don’t mean why is she at the funeral.
That’s fine. She may have had a good connection with the family. She may also have a good connection with the dude in the scenario.
All of this is fine.
The equation I’m talking about is the overstepping of boundaries in regards to the man. It’s not appropriate for her to do all of that for somebody else’s man, especially when his own partner can’t be there.
It would be weird as fukk if an ex tried to cover all my expenses for anything when my significant other was absent.
You really don’t see how inappropriate that looks? Hell my family might have even confronted me if I was there with an ex. They don’t play that foolishness

You can be cool with an ex without being extra and disrespectful or inappropriate IMO. Stop by, interact with the family, express your condolences and bounce.
But all this “Im going to cover everything for you and we can ride together to the funeral and I’ve got a hotel room for you and…”
Nah.