Taking one or both of the older ones it will help. My neighbor had twins after having 2 older kids, every time I go to the park with my twins I swing by and offer to take the older ones. Sometimes even an hour of relief helps. Another thing can be to offer to get stuff when going to Costco or other stores for yourself. Most importantly, don't call just show up and help (as long as your friend is ok with that)... With that many little ones there's no time to answer the phone or to even ask for help. And btw be aware of the high risk for post partum depression with multiples.
Reply to Friend going to have 3 under 2 😳