I'm so sorry, imissdow.
In the 3 1/2 years since LH's death, my father, two favorite aunts and an uncle have passed, plus an uncle of LH. I only attended my father's services. He was 93, so his/theirs were, I don't know?, natural deaths?? Not quite sure how to put that, but definitely in keeping with what is considered as the natural order of things. Even tho I was at peace with my father's passing, I still struggled during the service, with some parts being very triggering, but I got thru it.
Don't know how I'd do with a younger friend's passing and services, though- oh, boy. I feel so for her husband and kids. Two of my kids were adopted, and when LH died, one of the first things one said was that now she'd lost two dads. (She's gone on to act out in significant ways, despite ongoing counseling.)
I know the family will appreciate your presence. Try to sit near an exit, so you can take a "restroom break" (make a run for it) if needed. My policy now for funerals and weddings.
Strength and Peace to you, during the services and ongoing. And for her family.