yep. She'll need to make sure the older child is settled in a structured routine before the twins show up.... and the twins could be early, so start planning now..
Daycare for my oldest was how I pulled it off. He went to a home daycare... and instantly started talking and being social. He was pretty good with the babies..... and too young to have the concept of jealousy.
I also kept a spiral notebook for each baby. at first, I had three, but when my oldest turned 2yrs old, he had enough words and a regular routine, so I didn't need to look back on his daily naps and food,etc. ... and writing down his milestones anymore....
Keeping the log-book is a huge help to track wet/soiled diapers, and figure out what their patterns of eating and sleeping...It is a huge help to keep it all straight. ... and if you have help, or share some responsibilities, everyone needs to document things in the book.
Trust me, she won't keep it all straight..... and I used to forget who ate what, or who pooped when. who got their vitamins....
Although they call 'em twins, each was very different, so if they were both crying (often), the solution for one may not work for the other.
A nice friend like you to volunteer a few hours of help each week is a big deal....If even just bringing over a pizza for dinner. It is even a great help to just hold a baby on your lap... they are happy and mom has one less baby crying for attention!
The good news is that after all that craziness, it can only get better... and it does.