Congratulations, great news!
My SIL has two sets of twins! I won't lie to you it was had work even with the first set, but it's just amazing seeing two babies at once. When she had her second set, my little girl used to say look mummy it's two babies!
She cried for days when she found out she was having another set, she just kept repeating "my life is over" lol! I suppose it was because she knew how hard it would be.
First set, two girls (7) and second set a boy and a girl (2)! Truly amazing!
You will cope, she did/does!