Hot water. Top of the line detergents. Borax. If she's using liquid fabric softeners, stop. (Over use of the liquid fabric softener leads to a waxy build up in fabric that will retain odor.)

If she has an old school top loader, stop the washer and leave the items to soak.

If none of the above work, then she may need to resort to some of the specialty products like 'Zero Odor', etc. (I don't have any experience with those.)

Two things come to mind. She may be overloading the washer...just because it fits doesn’t mean it all belongs in one load. I’ve seen my kids do that for years (now in 30’s). The other is that she may need to add something to help. When my son who sweats A LOT played football you can imagine what his clothes were like everyday after practice. I used to add an Arm and Hammer product (like baking soda or borax?) to the laundry with his things. I didn’t have a front loader then, but it worked.

can i add baking soda to a front loader? My sick dog had diarrhea on a polyester bedspread and the smell won’t come out although I’ve washed twice using white vinegar in addition to detergent

Yes Nancy...you can add baking soda to a front loader.

I will usually use 1 or 2 tablespoons to a load but you may add more.

And try Dreft (POWDER). It's able to remove baby poo smell.

Neither vinegar nor baking soda will remove odor. That requires hot water -- over 140 F- and an excellent detergent like Persil or Tide.