Phoebe's name was revealed in New X-Men (1st series) #149, Celeste's in #153 and Mindee's in #156. Mindee was originally intended to be named Irma by Grant Morrison (spelling out S.P.I.C.E. girls with the Cuckoos' first initials), but he left before her name saw print. Mindee was referred to as "AKA Irma" in Uncanny X-Men (1st series) #513, but both names have been used interchangeably since.
Originally a group of five, their sisters Sophie and Esme died in New X-Men (1st series) #137 and #150, respectively.
They were called Weapon XV units 01, 03 and 04 in New X-Men (1st series) #154. Assuming an alphabetical order for the numbering, that would make Esme unit 02 and Sophie unit 05.