Phoebe also counts, since she has a twin sister named Ursula and herself gave birth to triplets (serving as a surrogate mother for her brother and his wife).
Phoebe doesn't count. Nine eggs were taken from Phoebe's sister-in-law, fertilized, and implanted in Phoebe. Three survived. This is very common with some forms of IVF and similar procedures; the SIL was likely given fertility drugs for several months so the doctors would have a sufficient number of eggs to work with. (Although since Friends aired, they've gotten better at survivability and through that keeping the number of kids born per round down.)
Coming back to where you started is not the same as never leaving. -Terry Pratchett
Phoebe doesn't count. Nine eggs were taken from Phoebe's sister-in-law, fertilized, and implanted in Phoebe. Three survived. This is very common with some forms of IVF and similar procedures; the SIL was likely given fertility drugs for several months so the doctors would have a sufficient number of eggs to work with. (Although since Friends aired, they've gotten better at survivability and through that keeping the number of kids born per round down.)
Coming back to where you started is not the same as never leaving. -Terry Pratchett