how to deal with MIL at a funeral

Context : I (F31) have been with my SO (F32) for about 7 years. She has been NC with her mom since before the start of our relationship, so I've never met her but have heard plenty about her and fully support her decision. SO maintained contact with her grandparents, and MIL has made attempts to contact her through her relatives over the years but SO has remained firm and never breached no contact.

So here's where I need advice. Her grandfather has been ill for some time and we just learned he is going to be passing on soon. We're going to go see him but I expect MIL might be there. SO would also like to go to the funeral, where MIL will surely be.

What is your advice for dealing with this situation? From everything I know, I'm fairly certain MIL will make a scene or try to talk to her. How can I be the best support possible? Should I run interference or let her handle it? We've discussed it, but she's unsure herself what she wants to do and is just anxious over the whole thing. Has anyone else dealt with this and how did you manage it?

Any advice is appreciated.